The European Space Agency's Planck satellite, launched on 14 May 2009, is the third-generation space experiment in the field of cosmic microwave background (CMB) research. It will image the anisotropies of the CMB over the whole sky, with unprecedented sensitivity ( ΔT T ∼ 2 × 10 −6 ) and angular resolution (∼5 arcmin). Planck will provide a major source of information relevant to many fundamental cosmological problems and will test current theories of the early evolution of the Universe and the origin of structure. It will also address a wide range of areas of astrophysical research related to the Milky Way as well as external galaxies and clusters of galaxies. The ability of Planck to measure polarization across a wide frequency range (30−350 GHz), with high precision and accuracy, and over the whole sky, will provide unique insight, not only into specific cosmological questions, but also into the properties of the interstellar medium. This paper is part of a series which describes the technical capabilities of the Planck scientific payload. It is based on the knowledge gathered during the on-ground calibration campaigns of the major subsystems, principally its telescope and its two scientific instruments, and of tests at fully integrated satellite level. It represents the best estimate before launch of the technical performance that the satellite and its payload will achieve in flight. In this paper, we summarise the main elements of the payload performance, which is described in detail in the accompanying papers. In addition, we describe the satellite performance elements which are most relevant for science, and provide an overview of the plans for scientific operations and data analysis.

This exploratory investigation examined the structural mechanism accounting for the enhanced compressive properties of heat-treated Kevlar-29 fibers. A novel theory was set forth that hydrogen-bond disruption and concurrent misorientation of crystallites may account for the observed augmentation of compressive properties. To examine the said theory, as-received Kevlar-29 fibers were characterized by thermogravimetric analysis and differential scanning calorimetry in an effort to determine if crosslinking and/or hydrogen-bond disruption was responsible for the improved behavior in compression. Additionally, Kevlar-29 fibers that had been exposed to treatment temperatures of 400, 440, and 470°C were profiled by Fourier transform infrared spectrophotometry to determine if crosslinking and/or hydrogen-bond obfuscation had been promoted. The results indicate that both mechanistic changes occurred within the Kevlar-29, albeit in different regions of the rigidrod polymer. In particular, heat treatment of poly-p-phenylene terephthalamide appears to have resulted in crosslinking of its skin region and hydrogen-bond disruption within the core realm.

SYNOPSISPBO [poly(p-phenylenebenzobisoxazole)] fiber has been shown to convert to an ordered carbon fiber without the need for stabilization. This article presents the first detailed analysis of the carbonization and graphitization behavior of this unique material. The carbonization process was modeled as a series of free-radical reactions, and thermogravimetric analysis was used to determine an activation energy of 76 f 6 kcal/mol for the thermal initiation of free radicals. The initiation reaction data then were applied to determine the temperature dependence of the termination reaction. Additionally, the development of long-range order in the graphitizing fiber was examined. The spacing between graphene planes was shown to decrease with increasing treatment temperature and soak duration. Carbonized PBO fibers developed more long-range order than carbon fibers produced from other polymers, which may partially explain why these PBO-based fibers display excellent lattice-dependent properties. Finally, an Arrhenius analysis found the activation energy for graphitization to be 120 f 17 kcal/mol.

This paper describes the development of rubrics that help evaluate student performance and relate that performance directly to the educational objectives of the program. Issues in accounting for different constituencies, selecting items for evaluation, and minimizing time required for data analysis are discussed. Aspects of testing the rubrics for consistency between different faculty raters are presented, as well as a specific example of how inconsistencies were addressed. Finally, a considerat ion of the difference between course and programmatic assessment and the applicability of rubric development to each type is discussed.

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In this study, large amounts of recoil compressive failure data were gathered for Kevlar-29 fibers. Once the dependence of failure frequency on stress level had been determined experimentally, two-parameter and four-parameter Weibull models were used to represent the data. An analysis of these results shows that each model represents the failure well, but that the four-parameter model offers little improvement over the two-parameter Weibull model. Deconstruction of the four-parameter model indicated that a single failure mechanism dominated and that this mechanism could be well represented by the two-parameter Weibull model. These results imply that while recoil compressive failure is more complicated than tensile failure, recoil failure is dominated by a single flaw distribution and can be represented by a more simple model than tensile failure.

In this paper, thermal treatments of Kevlar-29 fiber resulted in a significant enhancement of compressive strength and corresponding decrease in tensile strength. These changes result from a decreased linearity at the macroscopic level in the fiber. Statistically designed experiments indicate that treatment temperature is the most significant variable in the thermal processing, while treatment soak time also played a role in the shift of properties.

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