Interview with Donald Millinger

For transcript, click the Download button above. For video index, click the link below. Donald M. Millinger (L\u2779) practiced business and commercial law in the Philadelphia area and served on a number of non-profit boards. He is married to Gary Clinton, former Dean of Student Affairs at Penn Law School. In 2017 they established the Clinton-Millinger Scholarship program

The Athena x-ray optics development and accommodation

The Athena mission, under study and preparation by ESA as its second Large-class science mission, requires the largest X-ray optics ever flown, building on a novel optics technology based on mono crystalline silicon. Referred to as Silicon Pore Optics technology (SPO), the optics is highly modular and benefits from technology spin-in from the semiconductor industry. The telescope aperture of about 2.5 meters is populated by around 700 mirror modules, accurately co-aligned to produce a common focus. The development of the SPO technology is a joint effort by European industrial and research entities, working together to address the challenges to demonstrate the imaging performance, robustness and efficient series production of the Athena optics. A technology development plan was established and is being regularly updated to reflect the latest developments, and is fully funded by the ESA technology development programmes. An industrial consortium was formed to ensure coherence of the individual technology development activities. The SPO technology uses precision machined mirror plates produced using the latest generation top quality 12 inch silicon wafers, which are assembled into rugged stacks. The surfaces of the mirror plates and the integral support structure is such, that no glue is required to join the individual mirror plates. Once accurately aligned with respect to each other, the surfaces of the mirror plates merge in a physical bonding process. The resultant SPO mirror modules are therefore very accurate and stable and can sustain the harsh conditions encountered during launch and are able to tolerate the space environment expected during operations. The accommodation of the Athena telescope is also innovative, relying on a hexapod mechanism to align the optics to the selected detector instruments located in the focal plane. System studies are complemented by dedicated technology development activities to demonstrate the capabilities before the adoption of the Athena mission

Evaluation of Indian rural solar electrification: A case study in Chhattisgarh

Despite the considerable efforts spent on village electrification schemes in India, there is a general lack of evaluation of impacts, successes and of failures. A case study in Chhattisgarh state in India has been carried out to assess what effect village electrification through solar power has had for the beneficiaries and whether technical and maintenance factors provide for the desired results set by Indian rural electrification policy. Consequences for the beneficiaries have been investigated through a field survey conducted in eleven villages with 158 respondents, maintenance factors have been investigated through interviews with engineers and operators, and technical factors through analysis of electricity output from micro-grids.In villages where the systems had been installed in the past two years, children studied on average 41 min more in the evenings, more than twice as much as before electrification. Dinner cooking commenced on average 36 min later, a sign of higher flexibility of time use and thus of women\u27s empowerment. Furthermore, the median household monthly kerosene use decreased by 2 l, or 67%, but commercial productive activities were found to be limited.75% of the 69 micro-grid power plants evaluated were found to have too little output to supply for the stated 6 h of daily light per household, and the capacity installed per household decreased with village size. Plant capacity factors were found to vary greatly, most likely an effect of poor installation and/or inferior components. A tendency to replace energy-saving lights with incandescent lights requiring more power per lumen was found, leading to a decrease in obtainable light output

The Design of Large Real-Time Systems: The Time-Triggered Approach

The time-triggered (TT) architecture approach supports the spatial partitioning of a large, distributed real-time system into a set of autonomous subsystems with small control-free data-sharing interfaces between them. This paper presents such a TT architecture and gives a detailed description of the interface between an autonomous time-triggered communication subsystem based on the TTP protocol and the host computer within a node of this architecture. This interface acts as a temporal firewall that eliminates the possibility of control error propagation from one subsystem to another subsystem. It thus facilitates the independent development and validation of the subsystems and supports the composability of the distributed architecture with respect to timeliness, validation, and certification

Interview with Donald Millinger

For transcript, click the Download button above. For video index, click the link below. Donald M. Millinger (L\u2779) practiced business and commercial law in the Philadelphia area and served on a number of non-profit boards. He is married to Gary Clinton, former Dean of Student Affairs at Penn Law School. In 2017 they established the Clinton-Millinger Scholarship program

IMEM2: a meteoroid environment model for the inner solar system

International audienceContext. The interplanetary dust complex is currently understood to be largely the result of dust production from Jupiter-family comets, with contributions also from longer-period comets (Halley- and Oort-type) and collisionally produced asteroidal dust.Aims. Here we develop a dynamical model of the interplanetary dust cloud from these source populations in order to develop a risk and hazard assessment tool for interplanetary meteoroids in the inner solar system.Methods. The long-duration (1 Myr) integrations of dust grains from Jupiter-family and Halley-type comets and main belt asteroids were used to generate simulated distributions that were compared to COBE infrared data, meteor data, and the diameter distribution of lunar microcraters. This allowed the constraint of various model parameters.Results. We present here the first attempt at generating a model that can simultaneously describe these sets of observations. Extended collisional lifetimes are found to be necessary for larger (radius ≥ 150 μm) particles. The observations are best fit with a differential size distribution that is steep (slope = 5) for radii ≥ 150 μm, and shallower (slope = 2) for smaller particles. At the Earth the model results in ~ 90–98% Jupiter-family comet meteoroids, and small contributions from asteroidal and Halley-type comet particles. In COBE data we find an approximately 80% contribution from Jupiter-family comet meteoroids and 20% from asteroidal particles. The resulting flux at the Earth is mostly within a factor of about two to three of published measurements