Contractor point of view for system development and test program

Industry's practice of testing space qualified hardware is examined. An overview of the Global Positioning System (GPS) Test Program is discussed from the component level to the sub-system compatibility tests with the space vehicle and finally to the launch site tests, all related to the Rubidium clock

The soft drop momentum sharing fraction z_g beyond leading-logarithmic accuracy

Grooming techniques, such as soft drop, play a central role in reducing sensitivity of jets to e.g. underlying event and hadronization at current collider experiments. The momentum sharing fraction zg, of the two branches in a jet that pass the soft drop condition, is one of the most important observables characterizing a collinear splitting inside the jet, and directly probes the QCD splitting functions. In this work, we present a factorization framework that enables a systematic calculation of the corresponding cross section beyond modified leading-logarithmic (MLL) accuracy, showing that this measurement is not only sensitive to the QCD charge but also the spin of the parton that initiates the jet. Our results at next-to-leading logarithmic (NLL′) accuracy include non-global logarithms, and provide a first meaningful assessment of the perturbative uncertainty. We present a comparison to the available experimental data from ALICE, ATLAS, and STAR and find excellent agreement

Social democracy, embeddedness and decommodification: On the conceptual innovations and intellectual affiliations of Karl Polanyi

Of the several debates that revolve around the work of the economic historian and political economist Karl Polanyi, one that continues to exercise minds concerns his analysis of, and political attitudes toward, post-war capitalism and the welfare state. Simplified a little, it is a debate with two sides. To borrow Iván Szelényi's terms, one side constructs a ‘hard’ Karl Polanyi, the other a ‘soft’ one. The former advocated a socialist mixed economy dominated by redistributive mechanisms. He was a radical socialist for whom the market should never be the dominant mechanism of economic coordination. His ‘soft’ alter ego insisted that the market system remain essentially intact but be complemented by redistributive mechanisms. The ‘double movement’ – the central thesis of his ‘Great Transformation’ – acts, in this reading, as a self-correcting mechanism that moderates the excesses of market fundamentalism; its author was positioned within the social-democratic mainstream for which the only realistic desirable goal is a regulated form of capitalism. In terms of textual evidence there is much to be said for both interpretations. In this article I suggest a different approach, one that focuses upon the meaning of Polanyi's concepts in relation to their socio-political and intellectual environment

Advanced structural analysis of a laser additive manufactured Zr-based bulk metallic glass along the build height

Additive manufacturing of bulk metallic glasses (BMGs) has opened this material class to an exciting new range of potential applications, as bulk-scale, net-shaped amorphous components can be fabricated in a single step. However, there exists a critical need to understand the structural details of additive manufactured BMGs and how the glassy structure is linked to the mechanical properties. Here, we present a study of structure and property variations along the build height for a laser powder bed fusion (LPBF) processed Zr-based BMG with composition Zr59.3Cu28.8Nb1.5Al10.4 commercially termed AMZ4, using hardness testing, calorimetry, positron annihilation spectroscopy, synchrotron X-ray diffraction, and transmission electron microscopy. A lower hardness, more rejuvenated glassy structure was found at the bottom of the build compared to the middle region of the build, with the structure and properties of the top region between the two. Such differences could not be attributed to variability in chemical composition or crystallisation; rather, the softer bottom region was found to have a larger medium range order cluster size, attributed to heat dissipation into the build plate during processing, which gave faster cooling rates and less reheating compared to the steady-state middle of the build. However, at the top of the build less reheating occurs compared to the middle, leading to a somewhat softer and less relaxed state

Electrical Conductivity Studies on Individual Conjugated Polymer Nanowires: Two-Probe and Four-Probe Results

<p>Abstract</p> <p>Two- and four-probe electrical measurements on individual conjugated polymer nanowires with different diameters ranging from 20 to 190 nm have been performed to study their conductivity and nanocontact resistance. The two-probe results reveal that all the measured polymer nanowires with different diameters are semiconducting. However, the four-probe results show that the measured polymer nanowires with diameters of 190, 95&#8211;100, 35&#8211;40 and 20&#8211;25 nm are lying in the insulating, critical, metallic and insulting regimes of metal&#8211;insulator transition, respectively. The 35&#8211;40 nm nanowire displays a metal&#8211;insulator transition at around 35 K. In addition, it was found that the nanocontact resistance is in the magnitude of 10⁴&#937; at room temperature, which is comparable to the intrinsic resistance of the nanowires. These results demonstrate that four-probe electrical measurement is necessary to explore the intrinsic electronic transport properties of isolated nanowires, especially in the case of metallic nanowires, because the metallic nature of the measured nanowires may be coved by the nanocontact resistance that cannot be excluded by a two-probe technique.</p

Actions of Calcium on Smooth Muscle a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72185/1/j.1749-6632.1988.tb33358.x.pd