Modeling and Analysis of Power Processing Systems

The feasibility of formulating a methodology for the modeling and analysis of aerospace electrical power processing systems is investigated. It is shown that a digital computer may be used in an interactive mode for the design, modeling, analysis, and comparison of power processing systems

Control Theory in Engineering

The subject matter of this book ranges from new control design methods to control theory applications in electrical and mechanical engineering and computers. The book covers certain aspects of control theory, including new methodologies, techniques, and applications. It promotes control theory in practical applications of these engineering domains and shows the way to disseminate researchers’ contributions in the field. This project presents applications that improve the properties and performance of control systems in analysis and design using a higher technical level of scientific attainment. The authors have included worked examples and case studies resulting from their research in the field. Readers will benefit from new solutions and answers to questions related to the emerging realm of control theory in engineering applications and its implementation

Definition study for photovoltaic residential prototype system

A site evaluation was performed to assess the relative merits of different regions of the country in terms of the suitability for experimental photovoltaic powered residences. Eight sites were selected based on evaluation criteria which included population, photovoltaic systems performance and the cost of electrical energy. A parametric sensitivity analysis was performed for four selected site locations. Analytical models were developed for four different power system implementation approaches. Using the model which represents a direct (or float) charge system implementation the performance sensitivity to the following parameter variations is reported: (1) solar roof slope angle; (2) ratio of the number of series cells in the solar array to the number of series cells in the lead-acid battery; and (3) battery size. For a Cleveland site location, a system with no on site energy storage and with a maximum power tracking inverter which feeds back excess power to the utility was shown to have 19 percent greater net system output than the second place system. The experiment test plan is described. The load control and data acquisition system and the data display panel for the residence are discussed

SYNTHESIS AND EVALUATION OF ANTIMICROBIAL ACTIVITY OF PHENYL AND FURAN-2-YL[1,2,4] TRIAZOLO[4,3-a]QUINOXALIN-4(5H)-ONE AND THEIR HYDRAZONE PRECURSORS

A variety of 1-(s-phenyl)-[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one (3a-3h) and 1-(s-furan-2-yl)-[1,2,4]triazolo[4,3- a]quinoxalin-4(5H)-one (5a-d) were synthesized from thermal annelation of corresponding hydrazones (2a-h) and (4a-d) respectively in the presence of ethylene glycol which is a high boiling solvent. The structures of the compounds prepared were confirmed by analytical and spectral data. Also, the newly synthesized compounds were evaluated for possible antimicrobial activity. 3-(2-(4-hydroxylbenzylidene)hydrazinyl)quinoxalin-2(1H)-one (2e) was the most active antibacterial agent while 1-(5-Chlorofuran-2-yl)-[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one (5c) stood out as the most potent antifungal agent

Evaluation of STOL navigation avionics

Research projects, including work on a vector magnetometer for aircraft attitude measurement, are summarized. The earth's electric field phenomena was investigated in its application to aircraft control and navigation. Research on electronic aircraft cabin noise suppression is reviewed and strapdown inertial reference unit technical support is outlined

Development and Construction of a new Photoelectron Imaging Spectrometer for Studying the Spectroscopy and Ultrafast Dynamics of Molecular Anions

We present a detailed account of the development, construction, and commissioning of a new experiment for studying the spectroscopy and ultrafast dynamics of molecular anions in the gas phase. The new instrument incorporates: an electrospray ionisation source, which is capable of generating a vast class of molecular anions; a Wiley-McLaren time-of-flight mass spectrometer; and a compact photoelectron imaging arrangement for anions, which negates the use of pulsed high voltages. We use this instrument in conjunction with a femtosecond laser system to perform the first ultrafast time-resolved photoelectron imaging experiments on molecular anions generated through electrospray ionisation. A method for reconstructing three dimensional charged particle distributions from their associated two dimensional projections on an imaging detector plane is described. This new method utilises: (1) onion-peeling in polar co-ordinates (POP) to perform the reconstruction; and (2) basis set concepts to significantly enhance the algorithms computational speed. We compare this new POP algorithm with other reconstruction algorithms, which shows that the method is as good as the benchmark pBASEX method in terms of accuracy. Importantly, we show that it is also computationally fast, allowing images to be reconstructed as they are acquired in a typical imaging experiment. Original work is presented which investigates the spectroscopy and ultrafast excited dynamics of the 7,7,8,8-tetracyanoquinodimethane (TCNQ) radical anion. The photoelectron spectrum of TCNQ– is measured at 3.1 eV, which is used to gain insight into the electronic structure and geometries of both the anion and neutral states. Time-resolved photoelectron imaging experiments explore the relaxation dynamics of its first excited 1 2B3u state, which we show undergoes internal conversion back to the 2B2g ground state on a timescale of 650 fs. Results also provide evidence of a wave packet motion on the excited state, which exhibits a characteristic frequency of 30 cm–1. Finally, we describe, for the first time, a formulism which allows ultrafast relaxation timescales to be extracted from the photoelectron angular distributions of isoenergetic photoelectron features. As an example, we use the time-resolved photoelectron angular distributions of a nearly isoenergetic feature in the photoelectron images of TCNQ–. From this model we extract a relaxation time for the 1 2B3u state, which quantitatively agrees with those extracted from fits to the features in the photoelectron spectra derived from the images

Space shuttle orbiter heat pipe applications. Volume 2: Final report

For abstract, see

Digital receiver study and implementation

Computer software was developed which makes it possible to use any general purpose computer with A/D conversion capability as a PSK receiver for low data rate telemetry processing. Carrier tracking, bit synchronization, and matched filter detection are all performed digitally. To aid in the implementation of optimum computer processors, a study of general digital processing techniques was performed which emphasized various techniques for digitizing general analog systems. In particular, the phase-locked loop was extensively analyzed as a typical non-linear communication element. Bayesian estimation techniques for PSK demodulation were studied. A hardware implementation of the digital Costas loop was developed

Design/cost tradeoff studies. Appendix A. Supporting analyses and tradeoffs, book 2. Earth Observatory Satellite system definition study (EOS)

Attitude reference systems for use with the Earth Observatory Satellite (EOS) are described. The systems considered are fixed and gimbaled star trackers, star mappers, and digital sun sensors. Covariance analyses were performed to determine performance for the most promising candidate in low altitude and synchronous orbits. The performance of attitude estimators that employ gyroscopes which are periodically updated by a star sensor is established by a single axis covariance analysis. The other systems considered are: (1) the propulsion system design, (2) electric power and electrical integration, (3) thermal control, (4) ground data processing, and (5) the test plan and cost reduction aspects of observatory integration and test

Space Programs Summary no. 37-38, volume IV FOR the period February 1, 1966 to March 31, 1966. Supporting research and advanced development

Supporting research in systems analysis, guidance and control, environmental simulation, space sciences, propulsion systems, and radio telecommunication