are available and no effective degradation or detoxifying process exists. Objective the long-range goal of this research effort would be to use the information gained from these proposed studies on cellular molecular organization to develop bacterial strains with greater metabolic stability. The achievement of this goal could greatly enhance the productivity of a waste treatment facility using these bacteria to degrade cresylic acid waste. How research contributes this work contributes directly to subarea 1.9, Environmental Protection and Toxicological Hazards'. This research will attempt to establish the basic structural elements responsible for the metabolism of orthodichlorobenzene and cresol by select bacteria and to determine the metabolic stability of this capability. Specific attempts will be made to determine which fundamental elements are responsible for cresol metabolism and to establish if paracresol utilization is controlled separately from the ortho and meta isomers. SUPPORTED BY U.S. Dept. of Defense, Air Force, Office of Scientific Research 6.0019, CRITERIA SUITABLE FOR G-SUIT/G-VALVE EVALUATION IN A HIGH G ACM ENVIRONMENT R.R. Burton, U.S. Dept. of Defense, Air Force, School of Aerospace Medicine, Brooks Air Force Base, San Antonio, Texas 78235 (DF322330) To develop criteria useful in evaluating g-protection resulting from anti-g suits and valves during aerial combat-type acceleration exposures. Various criteria will be evaluated relative to g-protection provided by anti-g devices during exposure to simulated aerial combat maneuvers (SACM). Criteria to be evaluated will include: (a) objective parameters, (b) subjective measurements, and (c) modeling methods. These criteria relative to various antig devices will be evaluated in SACM-types of environments. Significantly correlated experimental criteria with improved g-protection and/or g-tolerances will verify their values as useful techniques in the quantification of anti-g devices used during exposure to aerial combat maneuvers. These criteria will be evaluated using data obtained from: (a) studies primarily designed to obtain these data and (b) studies primarily developed for other reasons--reevaluate data relative to usefulness as a tool to evaluate anti-g devices. These data will be summarized and evaluated in a technical review as the final product. SUPPORTED BY U.S. Dept. of Defense, Air Force, School of Aerospace Medicine 6.0020, AEROMEDICAL EVACUATION EQUIPMENT M. Chandler, U.S. Dept. of Defense, Air Force, School of Aerospace Medicine, Brooks Air Force Base, San Antonio, Texas 78235 (DF322090) To test and evaluate newly developed (commercial or inhouse) items of medical material to determine their effectiveness in aeromedical evacuation. The biomedical systems branch has an ongoing program of evaluating medical material items to satisfy identified operational requirements for aeromedical evacuation. Performance criteria have been established to insure that medical equipment items meet stated operational requirements. Current state-of-the-art of medical material technology will be continually assessed. The test program normally consists of six major areas, patient-user safety, operational specifications, environmental effects, electrical and mechanical characteristics, and human factors. Each area is subdivided into specific engineering tests or evaluations. When the test program is completed, the results are compiled and a report is sent to the field. The information is kept of file and updated or modified as user test reports are received. This is a continuation of part of the work formerly documented under work unit 7755-15-02. SUPPORTED BY U.S. Dept. of Defense, Air Force, School of Aerospace Medicine To provide comprehensive electrodiagnoistics for night vision evaluation in USAF aircrew members referred to USAFSAM, to gain insight into the processes of night vision disorders through the use of electrophysiology, to advance understanding of basic visual mechanisms objectively with the use of electrical technology. Application of current technology using using averaging computers, storage oscilloscopes, RF shielded rooms, and other equipment will be continued in evaluating visual physiology. Improved stimuli (integrating spheres) and recording devices (electrodes) will be utilized to advance the quality and scope of collected data. Research into underlying visual mechanisms and processes will be pursued. Efforts previously under work unit 7755-09-04. RELATIONSHIP ΤΟ 6.0022, EAR LOBE CREASE CORONARY ARTERY DISEASE IN HUMANS H.H. Hanna, U.S. Dept. of Defense, Air Force, School of Aerospace Medicine, Brooks Air Force Base, San Antonio, Texas 78235 (DF321910) To determine the incidence of significant ear lobe creases in various age groups of selected apparently asymptomatic individuals and to verify the reported correlation of ear lobe creases with coronary artery disease. Patients referred to the aeromedical consultation service will have a color photograph made of each ear lobe to document the presence or absence of skin creases. In those individuals who later have cardiac catheterization with coronary angiography, correlation of ear lobe creases with coronary artery disease will be determined. Those individuals who do not have cardiac catheterization will comprise the control group for incidence of ear lobe creases. This work was formerly documented under 7755-08-04. SUPPORTED BY U.S. Dept. of Defense, Air Force, School of 6.0023, GLAUCOMA/OCUSERT EVALUATION T.J. Tredici, U.S. Dept. of Defense, Air Force, School of Aerospace Medicine, Brooks Air Force Base, San Antonio, Texas 78235 (DF323080) Work unit 7755-16-03, Glaucoma, defines the broad guidelines to be used for identification, follow-up, and treatment of the majority of USAF flying personnel with glaucoma. This work unit deals with those individuals who cannot be treated with the presently recommended drugs (epinephrine derivatives) or who can no longer be controlled by this medication. Pilocarpine is by far the most useful drug available to control the intraocular pressure. Unfortunately, its side effects (myopia and miosis) preclude its use in flying personnel. Pilocarpine in the new delivery system (Ocusert) has recently been developed by Alza Corporation. It is a controlled release wafer that is inserted into the conjunctival sac and changed once weekly. It is reported to have only minimal visual side effects. If so, this would be ideal for flying personnel in need of treatment for glaucoma. Glaucoma patients being treated with Ocusert at the Ophthalmology Branch, USAFSAM, referred by flight surgeons or the USAF Surgeon General's office, will be closely followed to assure that the drug does not cause a significant decrement to the visual function. These data will be used to formulate new suggestions and regulations for the treatment of glaucoma in flying personnel. SUPPORTED BY U.S. Dept. of Defense, Air Force, School of Aerospace Medicine stress, etc. These factors may affect military performance to a degree that would limit an individual's effectiveness in a man/machine system. The results of these studies should provide carefully controlled, quantitative laboratory assessments of women's performance under standard and nonstandard work conditions as a member of the military team. A comparison of data from the proposed study and data already collected on males will provide crucial information concerning any differences between homogenous crews of females as compared to males. Deficiency as more and more women occupy operational positions, a data base on their physiological capabilities and limitations is required. Objective - this effort will explore the effects of the ovarian cycle and the sex of the subject on work performance. The primary focus of the research is on the effects of ovarian cycling on the work performance of women, including an assessment of the interactive effects of menstruation with a stressor known to produce decrements in work performance, continuous work, and consequent sleep loss. Comparison of the data obtained on female subjects to that of other studies using male subjects employing the same work situation, previously conducted by personnel of this laboratory, will permit some assessment of the effects of sex on work performance as well. How research contributes this research contributes directly to RO 1.5, 'Aerospace Medicine and RO 1.6, 'Habitable Crew Environments in Air Force Operations'. The research will be conducted utilizing the standardized procedures of the synthetic-work approach to performance assessment. It employs a Multiple-Task Performance Battery (MTPB) to create within the laboratory a synthetic-work situation in which systematic assessments of work behavior can be made. (). Moreno, University of Puerto Rico, Rio Piedras Campus, Graduate School, Rio Piedras, Puerto Rico 00931 (ENG78-16787) The mathematical structure of a relatively new class of algebraic codes, Goppa Codes, used in communication and computing systems is being studied. Specifically, the following problems on binary, irreducible Goppa Codes with maximal block length are being investigated: (1) The information content of the Goppa codes, (2) New symmetries of Goppa codes, (3) The relationship between symmetries of two different Goppa codes and their error-correcting capabilities, (4) The improvement of the information content of some Goppa codes. The rate, minimum distance, and methods of improving these codes are sought. Algebraic codes are being employed successfully in some applications including space communications and high-density storage of data in computers. SUPPORTED BY U.S. National Science Foundation, Div. of Engineering Unknown, Log An Inc., 924 Westwood Blvd., Los Angeles, California 90024 (FA78WA-4109; FA161207 (TRAIS NO.)) The contractor shall install and maintain the PROMAP Program in the computer at the Department of Transportation Computer Center (TCC). The contractor shall have qualified personnel available on an ‘on-call' basis for interpretation of PROMAP status reports and projections; analysis of alternative courses of action; evaluation of trends; control of schedule and budget; and implementation of final outputs. In the event the TCC computer is unable to meet abnormal turnaround dates, the contractor shall provide pick-up and computer processing of activity data on an 'on-call' basis for these non-routine updates. SUPPORTED BY U.S. Dept. of Transportation, Federal Aviation Admin. 7.0003, GENERAL SIMILARITY SOLUTION OF THE TRICOMI EQUATION AND ITS APPLICATIONS J.D. Cole, University of California, Los Angeles Campus, School of Letters & Science, Dept. of Mathematics, 405 Hilgard Ave., Los Angeles, California 90024 (DF046600; AFOSR-77-3173) AF function - aerospace vehicle design. Opportunity possibly more economical transonic wing design. Objective - improved analytic techniques for compressible flow problems. How work contributes -numerical parameter optimization is often aided by analytic understanding. The general similarity solution for a partial differential equation can be found by studying the infinitesimals of the group of transformations which leave the equation invariant. The Tricomi equation is the simplest partial differential equation of mixed type. The four parameter group which leaves the Tricomi equation invariant has been found. It is proposed to study the resulting similarity forms, the geometry of the similarity curves, and to construct the general solution of the ordinary differential equations which result. These solutions can be interpreted as the hodograph streamlines of a transonic flow. Thus new classes of practical flows will be generated by interpretation of particular similarity solutions and their superposition if necessary. SUPPORTED BY U.S. Dept. of Defense, Air Force, Office of Scientific Research 7.0004, NONPARAMETRIC STATISTICS AF function signal detection and communication, meteorology and forecasting airfield ceiling conditions, missile targeting and target localization. Opportunity continuation of the work in progress by the principal investigator will have farreaching impact on the above problems. Objective - develop the statistical methodologies applicable to problems in communication theory, signal detection, meteorology and forecasting, target localization and missile targeting. How work contributes - the development of these statistical methods will make available sound and easily implementable theoretical basis for the development of hardware and methods related to the above-mentioned Air Force functions. Some of the specific areas in which it is proposed to do research are (a) discriminant analysis, (b) some distributions theory problems encountered in the analysis of circular data, (c) asymptotic theory of rank order statistics, (d) development of nonparametric procedures to different classes of stochastic processes, (e) order statistics from the non normal populations, (f) multivariate procedures based on spherical distributions. SUPPORTED BY U.S. Dept. of Defense, Air Force, Office of Scientific Research 7.0005, IMPROVEMENTS ΤΟ CDC OFF-LINE MAINTENANCE SOFTWARE AND CDC TEST CART SOFTWARE GW. Howe, Raytheon Co., Boston Post Rd., Wayland, Massachusetts 01778 (FA77NA-4008; FA160003 (TRAIS NO.)) Design, develop, produce, document, test, and deliver an enhanced Off-Line Maintenance Software (OLMS) Package and an enhanced Test Cart Software (TCS) Package for the CDC System. The initial task for both the OLMS and Test Cart work effort consists of a study phase prior to any program development. The study phases cover an analysis and design effort for the respective software improvements. The end product of the study is to be the generation of a Computer Program Functional Specification (CPFS) defining all improvements to be incorporated into these software packages. SUPPORTED BY U.S. Dept. of Transportation, Federal Aviation Admin. 7.0006, NUMERICAL METHODS FOR PROBLEMS ON ENVIRONMENTAL EFFECTS IN AEROSPACE VEHICLES R.S. Varga, Kent State University, School of Arts & Sciences, Dept. of Mathematics, Hilltop Dr., Kent, Ohio 44240 (DF038960; AFOSR-74-2729) AF function - the design of chemical laser devices, the study of nuclear weapons effects on structures and aerospace vehicles. Opportunity the use of Pade approximants to develop computational algorithms for solving the stiff differential equations arising in the application areas listed above may provide useful tools to engineers and scientists in Air Force laboratories. Objective - this research intends to investigate the location of the zeros of certain functions, implicit Runge-Kutta methods for solving still systems of ordinary differential equations, the stability of such methods and to perform numerical experiments with these methods. How work contributes - techniques to be developed under this research effort may lead to the development of effective computational tools. This research will examine the condition under which certain entire functions contain no zeros in specified parabolic regions in the complex plane. Will determine, if possible, a class of entire functions which with all its partial sums have no zeros in specified infinite regions of the complex plane. Implicit Runge-Kutta methods based on the repeated inversion of a fixed matrix will be investigated. In addition, numerical testing of the techniques developed will be accomplished. SUPPORTED BY U.S. Dept. of Defense, Air Force, Office of Scientific Research 7.0007, NASTRAN COMPUTER PROGRAM J.R. Johnson, U.S. Dept. of Defense, Air Force, Flight Dynamics Lab., Wright Patterson A.F.B., Dayton, Ohio 45433 (DF132120) Structural stength, integrity, service life and minimum weight are vital concerns in the design and analysis of aerospace vehicles to insure that they perform the intended mission. The objective of this effort is to develop efficient general purpose finite element structural analytical methods that will directly support the design and analysis of structures for strategic, tactical, training and logistic aerospace vehicles. The successful accomplishment of this objective will insure the ready capability to provide the analysis support for aerospace systems, such as the B-1, CCV and RPV, with a minimum of elapsed time, and to provide a NASTRAN focal point for the WPAFB NASTRAN users group. Coordinate the efforts of the users group. Provide consultation and direction as required to use, maintain and modify the computer program. Serve on the HQ NASA NASTRAN Advisory Group (NAG). SUPPORTED BY U.S. Dept. of Defense, Air Force, Flight 7.0008, APPLIED DIFFERENTIAL EQUATIONS M.G. Crandall, University of Wisconsin, Madison Campus, Mathematics Research Center, 610 Walnut St., Madison, Wisconsin 53706 (DA0M9690; DAAG29 75 C 0024) Continue and extend studies of differential equations in order to provide a better foundation for the design of Army weapons, vehicles, aircraft, communications and supply systems, and protective equipment. There will be special attention to the influence of boundary conditions on the character of the solutions, special study of the asymptotic behavior of the solutions near singular points, and special attention to other topics from PHYSICS Includes Physics (general), Acoustics, Atomic and Molecular Physics; Nuclear and High-energy Physics, Optics, Plasma Physics, Solid-state Physics; Thermodynamics and Statistical Physics. For Related Information See Also Engineering. 8.0001, THEORETICAL ANALYSIS OF SCATTERING OF A LASER BEAM FROM ROUGH SURFACES 13913-P C.C. Sung, University of Alabama in Huntsville, School of Science & Engineering, Dept. of Physics, Huntsville, Alabama 35807 (DA0F8901, DAAG29 77 GOÓ51) To obtain surface characteristics such as roughness, curvature and velocity of an object using the coherent radiation of a laser reflected from the surface. Relevance the research has direct relevance to ongoing work at MICOM on reentry vehicles and reentry vehicle materials and ECOM on battlefield-surveillance, target acquisition and fire control. Speckle statistics and the relationship between the average angular irradiance distribution of a reflected laser beam to the surface properties of a random rough surface will be investigated. SUPPORTED BY U.S. Dept. of Defense, Army Materiel Development & Readiness Command, Army Research Office 8.0002, OPTICAL PROPERTIES OF SMALL BAND GAP SEMICONDUCTORS SUBJECT TO LASER EXCITATION D.L. Smith, California Inst. of Technology, Graduate School, Dept. of Applied Physics, 1201 E. California Blvd., Pasadena, California 91109 (DF047320; AFOSR-77-3216) AF function aerospace communications, surveillance and detection systems require electrooptical devices which exploit the special properties and interactions of infrared radiation with solid-state materials. Opportunity - materials sensitive in the far infrared region of the electromagnetic spectrum are important components of airborne and spaceborne surveillance systems. Objective this study investigates the effect of carriers generated by laser illumination on the optical properties of small band gap semiconductors of interest for the construction of infrared sources and detectors, and the behavior of a nonequilibrium distribution of electrons and holes produced in a small band gap semiconductor like Hg1-xCdxTe. More specifically the objectives are to determine the nature of the quantum states formed by optically excited electrons and holes in HgCdTe under different conditions of carrier density and temperature, the energy and lifetimes of these states, the effect of carriers in these states on the electrical and optical properties of the material, and the effect of free holes in Ge on the absorption of intense infrared radiation. How work contributes -infrared detectors and tunable infrared sources of coherent radiation require solid-state materials with narrow band gaps, controlled carrier concentrations and doping to provide optimal performance characteristics. Such investigations should lead to the formulation of models and mechanisms of linear and nonlinear interactions of laser light with solids and the understanding of basic parameters that control the properties and behavior of narrow band gap semiconductors. (1) Compute oscillator strengths and Auger transition rates for bound excitons in HgCdTe and determine the dependence of these rates on impurity depth and alloy composition. (2) Formulate a theory of the broadening of bound carrier energies due to compositional disorder in semiconductor alloys. (3) Perform high-resolution absorption and luminescence measurements in Hg1-xCdxTe in the composition range (0.25 is less than or equivalent to x is less than or equivalent to ().45) and the temperature range (4 degrees K is less than or equivalent to t is less than or equivalent to 80 degrees K). (4) Initiate absorption and gain measurements in HgCdTe which is being excited by a high-intensity pump laser. (5) Initiate a theoretical study of saturable absorption in p-type Ge at the CO2 laser frequency. SUPPORTED BY U.S. Dept. of Defense, Air Force, Office of Scientific Research AF function microwave solid-state electronic devices are essential components of Air Force surveillance, countermeasure and communication systems. Opportunity - improved performance of devices that generate and process microwave signals can be expected from use of solid-state materials that are more uniformly doped while maintaining low defect concentrations. Objective the objective of this research is to study a new method of doping high device quality GaAs crystalline materials. How work contributes this research should perfect a method for preparing high-quality GaAs device material with highly reproducible, homogeneous, and well-controlled doping characteristics. The objective of this experimental research program is to measure the static dielectric constant of semiconductors with a symmetry-induced zero energy gap, and to determine its dependence on external parameters. In semiconductors belonging to this class the dielectric constant is theoretically predicted to have an anomalous behavior resulting from an inter-band contribution, which in pure materials at very low temperatures approaches a singularity. Microwave and millimeter wave propagation in these materials, in the presence of an external DC magnetic field, is under certain conditions strongly dependent on the static dielectric constant. These wave propagation effects will be used to measure the value of static dielectric field, on composition, on hydrostatic pressure, and on the direction which the magnetic field makes with the crystallographic axes. SUPPORTED BY U.S. National Science Foundation, Div. of Materials Research 8.0005, LASER LIGHT SCATTERING STUDIES OF EXCITON AND FREE CARRIER RELAXATION IN PURE AND IMPLANTED SEMICONDUCTORS A.D. Compaan, Kansas State University, School of Arts & Sciences, Dept. of Physics, Anderson Hall, Manhattan, Kansas 66502 (DMR7820607) Experiments to study high-density exciton interactions in ion-implanted Cu2O, previously supported by Grant No. DMR7600371, will be continued and extended to shorter wavelengths. A high power (100 kw) pulsed dye laser will be used to create exciton densities large enough to observe changes in the photoluminescence spectrum due to exciton-exciton scattering and thermalization effects. This program wll also include resonance Raman studies of other ion-implanted semiconductors such as GaAs. SUPPORTED BY U.S. National Science Foundation, Div. of Materials Research PROCESSES AND CHEMICAL REACTIONS AF function - the Air Force is interested in the development of high-power laser technology. Deficiency techniques are needed for obtaining more detailed information on reaction rates, cross-sections, rate constants, and mechanisms. Objective - a new technique is being developed which permits measurements of the velocity dependence of energy transfer cross-sections of specific 8.0007, Research previously supported by DMR7616597. Theoretical studies of mixed-valent samarium compounds, structural and magnetic properties of alkali superoxides, and strong correlation effects on electronic states in crystalline solids, will be carried out. A variety of calculations will be made and compared with experiments in order to shed light on the microscopic nature of the ground and excited states of the mixed-valent phase of SmS and related compounds. Hopefully the results will explain a number of unusual experimental results, e.g., the neutron form factor and first order phase boundary. The main thrust of the calculations in the superoxides will be to understand the structural phase transitions involving orientational ordering of the 02-molecular ions. Also, the calculations will involve investigation of the effect on the electronic properties of the rich variety of structures observed in these materials. The purpose of the proposed research on strong correlation effects is to investigate a new variational definition of one-electron states (Bloch functions) in crystalline solids for highly correlated narrow-band electrons which overcomes serious deficiencies in earlier attempts. SUPPORTED BY U.S. National Science Foundation, Div. of Materials Research L.M. Sander, University of Michigan, Ann Arbor Campus, School of Engineering, Dept. of Physics, Ann Arbor, Michigan 48104 (DMR7825012) Research previously supported by DMR7412003. Theoretical work will be carried out in two major areas of solid-state physics: studies of the electron-hole liquid, and general studies of the electron gas in metals. The methods used stem from the density-functional theory of Hohenberg, Kohn and Sham. Particular areas to be investigated are: surface effects in small electron-hole droplets; droplets in doped semiconductor; various aspects of the Wigner and Mott transitions of the electron gas; pseudo-potential theory of metal surfaces; the temperature-dependence of the surface energy of metals; and a possible application of density functionals to liquid helium. This is the first year of a three-year continuing grant. SUPPORTED BY U.S. National Science Foundation, Div. of Materials Research 8.0009, THE ANATOMY OF THE X-RAY AND NEUTRON PRODUCTION SCALING LAWS IN THE PLASMA FOCUS W.H. Bostick, Stevens Inst. of Technology, School of Engineering, Dept. of Physics, Castle Point, New Jersey 07030 (DF028840; AFOSR-75-2754) AF function - operation of high-altitude vehicles in a post nuclear explosion environment, development of electromagnetic weapons, space and ionospheric communications as well as countermeasures, demand the fundamental understanding of energy transformation processes occurring in plasmas such as magnetic vortex annihilation and emission of photons and particles. Defi ciency - the aforementioned information required to design advanced equipment is not available today. Its acquisition may be realized by a well-planned theoretical and experimental research. Objective - this project will investigate both theoretically and experimentally the fundamental characteristics of energy transformation processes. It will specifically study the anatomy of the xray and neutron production similarity and scaling laws in the dense plasma focus. Contribution - this work is a part of a comprehensive program of plasma research for the development of an x-ray radiation source for simulation of nuclear weapon effects, the development of advanced electromagnetic weapons (laser and particle beam), the development of space and ionospheric communications, and the development of countermeasures. This project will perform theoretical and experimental work to understand the energy transformation processes occurring in a dense plasma focus. They will perform the following - a. Measurement of the electron beams and x-ray production with current transformers, Faraday cups, and hard x-ray collimators, b. They will use paraffin collimators to explore more precisely the energy spectrum of the plasma focus, c. They will pursue the study of the anatomy of the scaling laws. They will operate the two plasma focus machines to study the aforementioned scaling laws. The scaling parameters are the peak voltage and the peak current, d. They will collaborate with two laboratories in Italy (Torino and Frascati) and one in Germany (Darmstadt) in order to cover a wider range of machine power. They will conduct a global survey with the Buenos Aires Plasma Physics Group of the operation of plasma focus machines. SUPPORTED BY U.S. Dept. of Defense, Air Force, Office of Scientific Research 8.0010, MOLECULAR SPECIES PRESENT IN THE NEUTRAL EFFLUX OF THE SOLID TEFLON PULSED PLASMA THRUSTER J.K. Hartman, Canisius College, School of Arts & Sciences, Dept. of Physics, Main & Jefferson Ave., Buffalo, New York 14208 (DF051960; AFOSR-78-3579) AF function - space systems, communications satellites. Deficiency the technology for reliable long-life repeating propulsion systems is not in hand. In part, this is due to lack of sufficient fundamental knowledge about the working fluid of plasma thrusters. Objective - this work will be concerned with performing a variety of mass spectrometer measurements on the plasmas generated in a small solid teflon pulse plasma thruster, in order to improve understanding of the neutral portion of the exhaust beam. How work contributes - it is hoped that the resulting improvement in knowledge will help alleviate users' years of spacecraft contamination and facilitate design of future plasma thrusters and spacecraft. A borrowed teflon pulse plasma thruster will be made part of a mass spectrometer-vacuum system. The concentration and velocity distributions of neutral species in the thruster exhaust will be measured under various operating conditions. SUPPORTED BY U.S. Dept. of Defense, Air Force, Office of Scientific Research Studies will be made predominantly for the Mossbauer elements, Au, Sn, Sb, Te, I and Fe, as pure materials or in alloys or compounds with each other or with other elements. This is the first year of a three-year continuing grant. SUPPORTED BY U.S. National Science Foundation, Div. of AND 8.0012, MAGNETIC PHASE TRANSITIONS GROUND STATE PROPERTIES OF MAGNETIC CRYSTALS J.L. Fry, University of Texas, Arlington Campus, Graduate School, Dept. of Physics, Arlington, Texas 76019 (DF043370; AFOSR-76-2981) AF function - this proposed research primarily falls in the 7.4 research objectives which deal with the theoretical and experimental investigations of electronic, optical, acoustic, thermal, magnetic and conducting properties of materials to evolve new and improved device concepts. In particular, the theoretical investigations of the magnetic phase transitions will be done to give a deeper understanding of the physics of magnetic properties in itinerant electron systems. The gaining of this understanding of the precise mechanisms involved lead to meaningful mathematical models which in turn form a more rational and less empirical device design. Deficiency - a wide range of basic research efforts that support the development of devices and device concepts are needed for the application of contemporary electronic electromagnetic technology in the operational Air Force. Most studies of magnetic properties utilize model Hamiltonians, and model potentials which leave a large number of uncertainties. Objective the major emphasis during the renewal period will be on a thorough study of magnetic phase transition calculations in a number of physically interesting magnetic systems. These calculations make use of the susceptibility studies and at present are based on the temperature Green's function method. Contribution - this research is a part of a comprehensive program in statistical mechanics to study phase transitions. During the renewal period Oct 1, 1977-Sep 30, 1978 they propose to expand the phase transition calculations from the simplest system and approximations to more complex magnetic systems of interest. By the beginning of the renewal period they expect to have the required computer programs completed and ready for use in more complicated transition metals and transition metal compounds. The major emphais during the renewal period will be on a thorough study of magnetic phase transition calculations in a number of physically interesting magnetic systems. These calculations make use of the susceptibility studies described above and at present are based on the temperature Green's function method which is briefly reviewed here. In the temperature Green's function formalism, which is based on the method of Martin and Schwinger as outlined by Fedders and Martin, the time dependence is contained in an imaginary dimensionless variable which also has a temperature dependence. (Text Abridged) 8.0011, METALS AND ALLOYS L.D. Roberts, University of North Carolina, Chapel Hill Campus, School of Arts & Sciences, Dept. of Physics, Chapel Hill, North Carolina 27514 (DMR7818916) Metals and alloys will be investigated through the use of a number of closely correlated experimental and theoretical methods. This work will be directed toward gaining more complete information about (a) the metal or alloy wave function in the inner, or core, region of the atoms, (b) the metal or alloy wave function in the immediate vicinity of the atoms, and (c) the forces binding the atoms. It is hoped that a comprehensive theoretical description will be obtained in terms of Relativistic Augmented Plane Wave band structure treatments, and that RAPW pseudopotential calculations can be done which will bear primarily on the alloy studies. The experimental studies will principally include Mossbauer effect measurements, x-ray chemical shift measurements, and impurity electrical resistance and magnetic studies including Kondo effect measurements. Some of this work will be done at high pressures and at low temperatures. R.F. Braunlich, Washington State University, School of Arts & Sciences, Dept. of Physics, Administration Bldg., Room 101, Pullman, Washington 99163 (DF052890; AFOSR-78-3650) AF function future high-performance aircraft will employ an increasing amount of adhesively bonded structures. Deficiency in order to obtain maximum strength, metal components are anodized to form a thin oxidized layer and the adhesive is then used to bond these layers together. The mechanical strength and other properties of the anodized oxide must be determined in order to insure compatability and strength in the bonded region. Objective the objective of this research is to examine the fracture dynamics and micromechanics of thin, anodized oxide films on metals by measuring the tribo-emission of charged particles during early stages of microcracking. How work contributes analysis of the emitted particles will provide greater understanding and optimization of the oxide films grown on metals prior to adhesive bonding. |