Engineering topics
Publications and source records attributed to Berg, M..
Space applications are complex systems that require intricate trade analyses for optimum implementations. We focus on a subset of the trade process, using classical reliability theory and SEU data, to illustrate appropriate TMR scheme selection.
A novel approach to dynamic SEE ADC testing is presented. The benefits of this test scheme versus prior implemented techniques include the ability to observe ADC SEE errors that are in the form of phase shifts, single bit upsets, bursts of disrupted signal composition, and device clock loss.
A viewgraph presentation on the development of a low cost, high speed tester reconfigurable Field Programmable Gata Array (FPGA) is shown. The topics include: 1) Introduction; 2) Objectives; 3) Tester Descriptions; 4) Tester Validations and Demonstrations; 5) Future Work; and 6) Summary.
A study of the effects of titania on selected properties of hafnia-rich mixed oxides in the system hafnia-zirconia-titania (HZT) was made in the region 5 to 20 mol percent titania. The studied properties included electrical conductivity, thermal expansion, and fracture strength and toughness. The effects of titania on the properties were studied for the reduced state as well as the oxidized state of the sintered mixed oxides. X-ray analysis showed that the materials were not always single phase. The oxidized compositions went from being monoclinic solid solutions at low titania additions to having three phases (two monoclinic and a titanate phase) at high additions of titania. The reduced compositions showed an increasing cubic phase presence mixed with the monoclinic phase as titania was added. The electrical conductivity increased with temperature at approximately 0.1 mhos/cm at 1700 C for all compositions. The thermal expansion coefficient decreased with increasing titania as did the monoclinic to tetragonal transformation temperature. The fracture strength of the oxidized bars tended to decrease with the addition of titania owing to the presence of the second phase titania. The fracture strength of the reduced bars exhibited a minimum corresponding to a two-phase region of monoclinic and cubic phases. When the second phases were suppressed, the titania tended to increase the fracture strength slightly in both the oxidized and reduced states. The fracture toughness followed similar trends.
An exploratory wind survey at an antenna complex was summarized statistically for application to future windmill designs. Data were collected at six locations from a total of 10 anemometers. Statistics include means, standard deviations, cubes, pattern factors, correlation coefficients, and exponents for power law profile of wind speed. Curves presented include: mean monthly wind speeds, moving averages, and diurnal variation patterns. It is concluded that three of the locations have sufficiently strong winds to justify consideration for windmill sites.