Long term trending of engineering data for the Hubble Space Telescope

A major goal in spacecraft engineering analysis is the detection of component failures before the fact. Trending is the process of monitoring subsystem states to discern unusual behaviors. This involves reducing vast amounts of data about a component or subsystem into a form that helps humans discern underlying patterns and correlations. A long term trending system has been developed for the Hubble Space Telescope. Besides processing the data for 988 distinct telemetry measurements each day, it produces plots of 477 important parameters for the entire 24 hours. Daily updates to the trend files also produce 339 thirty day trend plots each month. The total system combines command procedures to control the execution of the C-based data processing program, user-written FORTRAN routines, and commercial off-the-shelf plotting software. This paper includes a discussion the performance of the trending system and of its limitations

Engineering Leadership Assessment Tool Profile

Numerous studies have been conducted stressing the importance of developing the professional skillset of engineers. This need has been further highlighted by the Engineering Criteria 2000 and by the National Academy of Engineers (Kumar and Hsiao, 2007, p. 19). Having realised the need to develop the professional skillset of engineers such as leadership, interpersonal skills, teamwork and communication, universities have started incorporating methods to hone these skills in their courses. However in today’s competitive world, every practice needs to be assessed and measured for accountability and effectiveness. Engineering education is no exception to this rule. There needs to be a tool that can assess the leadership abilities of engineering students to see if courses are meeting their desired outcomes. This led to the creation of an assessment tool that can be used by students to self-assess themselves or by faculty to gauge a students’ strengths and weaknesses. The tool reports personalised scores which can be compared with data obtained from a survey completed by 700 students to establish a baseline of leadership skills in camparison to one’s peers. The tool can also guide students in selecting courses that can strengthen areas that they are currently lacking in. The tool, once validated, can be implemented on a larger scale and even be used in other universities

Low frequency sound propagation in activated carbon

Activated carbon can adsorb and desorb gas molecules onto and off its surface. Research has examined whether this sorption affects low frequency sound waves, with pressures typical of audible sound, interacting with granular activated carbon. Impedance tube measurements were undertaken examining the resonant frequencies of Helmholtz resonators with different backing materials. It was found that the addition of activated carbon increased the compliance of the backing volume. The effect was observed up to the highest frequency measured (500 Hz), but was most significant at lower frequencies (at higher frequencies another phenomenon can explain the behavior). An apparatus was constructed to measure the effective porosity of the activated carbon as well as the number of moles adsorbed at sound pressures between 104 and 118 dB and low frequencies between 20 and 55 Hz. Whilst the results were consistent with adsorption affecting sound propagation, other phenomena cannot be ruled out. Measurements of sorption isotherms showed that additional energy losses can be caused by water vapor condensing onto and then evaporating from the surface of the material. However, the excess absorption measured for low frequency sound waves is primarily caused by decreases in surface reactance rather than changes in surface resistance

Meet the fellows: Everything about ISV

[Extract] On September 14th, 2021, a special session was held as part of the 2021 ISV Virtual Annual Congress to review the history of International Society for Vaccines (ISV). Congress Chair Dr. Manon Cox (MC) was the moderator of this session, interacting with three ISV fellows: Drs. Denise Doolan (DD), Shan Lu (SL) and Ted Ross (TR)

Recombinational DNA Repair: The RecF and RecR Proteins Limit the Extension of RecA Filaments beyond Single-Strand DNA Gaps

AbstractIn the presence of both the RecF and RecR proteins, RecA filament extension from a single strand gap into adjoining duplex DNA is attenuated. RecR protein alone has no effect, and RecF protein alone has a reduced activity. The RecFR complexes bind randomly, primarily to the duplex regions of the DNA, and the extension of the RecA filament is halted at the first complex encountered. A very slow lengthening of RecA filaments observed in the presence of RecFR is virtually eliminated when RecF is replaced with an RecF mutant protein that does not hydrolyze ATP. These observations are incorporated into an expanded model for the functions of RecF, RecO, and RecR proteins in the early stages of postreplication DNA repair