Study of the Effect of Transport Current and Combined Transverse and Longitudinal Fields on the AC Loss in NET Prototype Conductors

AC losses in cables carrying DC as well as AC transport currents at different DC background fields up to 2T have been measured on three types of Nb3Sn subcables in a new test facility. In this facility it is possible to apply sinusoidal transverse AC fields up to dB/dt=5T/s and longitudinal AC fields up to dB/dt=30T/s separately and simultaneously. The AC loss is measured with a calorimetric method. Simultaneously applied transverse and longitudinal fields can result in a loss which exceeds the added contributions of the separate applied AC fields. Within the measured range it is about correct (within 10%) to add the loss components due to DC transport current up to 10 kA and both applied transverse and longitudinal AC fields. The measured total loss is always above the sum of the loss component

Tightness of lead times

This paper introduces a general, formal treatment of dynamic constraints, i.e., constraints on the state changes that are allowed in a given state space. Such dynamic constraints can be seen as representations of "real world" constraints in a managerial context. The notions of transition, reversible and irreversible transition, and transition relation will be introduced. The link with Kripke models (for modal logics) is also made explicit. Several (subtle) examples of dynamic constraints will be given. Some important classes of dynamic constraints in a database context will be identified, e.g. various forms of cumulativity, non-decreasing values, constraints on initial and final values, life cycles, changing life cycles, and transition and constant dependencies. Several properties of these dependencies will be treated. For instance, it turns out that functional dependencies can be considered as "degenerated" transition dependencies. Also, the distinction between primary keys and alternate keys is reexamined, from a dynamic point of view.

Delivering Quality Early Learning In Low-Resource Settings: Progress And Challenges In Ethiopia

The potential of high quality early childhood care and education ECCE programmes to deliver positive outcomes for children and society is well recognised. But delivering on this potential presents huge challenges, especially in low and middle income countries. This final working paper in the Transitions in Early Childhood series focusses on Ethiopia. While in many respects Ethiopia is a success story of Education For All, in terms of increased enrolments in primary education, the early years of schooling is faced with numerous access and quality challenges. This working paper reviews the government of Ethiopia's 2010 policy framework for ECCE and highlights these different challenges in rural and urban areas of Ethiopia, drawing on survey and qualitative research data collected as part of Young Lives longitudinal research

Marnda Gardairri: Facilitation of an Indigenous Ranger Rock Art Workshop

The Marnda Gardairri Indigenous Rangers Workshop was held from 3–5 October 2017 on the Burrup Peninsula in the Pilbara region of Western Australia. The event, which was hosted by the Murujuga Aboriginal Corporation (MAC), brought together rangers from across Australia to discuss rock art conservation and management. The workshop was given the title ‘Marnda Gardairri’ as this means rock scratching/engraving on the Burrup Peninsula. The workshop was developed by MAC in collaborative partnership with Rio Tinto Iron Ore-Pilbara Operations and the Nulungu Research Institute (The University of Notre Dame Australia). Rio Tinto and Woodside Petroleum funded the workshop, with Mel Marshall and Lynley Wallis of Nulungu engaged to coordinate and facilitate the event, assisted by Kate Golson.https://researchonline.nd.edu.au/nulungu_insights/1002/thumbnail.jp

The Effect of Inter-bundle Resistive Barriers on Coupling Loss, Current Distribution and DC Performance in ITER Conductors

The role of inter-bundle resistive barriers (metal sheet wraps), introduced to reduce the inter-bundle coupling loss in multistage cabled Cable-In-Conduit Conductors (CICC) for the International Thermonuclear Experimental Reactor (ITER) is evaluated, based on results gained recently on short sample experiments in the Twente Cable Press and SULTAN. The obvious benefit of limiting the inter bundle coupling loss unavoidably goes together with impeding the redistribution of nonuniform currents in the coil winding introduced at the terminations, as well as reduction of the heat exchange between the bundles. Six-element numerical electromagnetic code simulations are presented that qualitatively explain the effect of wraps on the DC performance, strongly depending on the testing geometry. The computations illustrate that wraps can reduce the DC performance in short sample tests. At the same time simulations of the Poloidal Field Coil Insert (PFCI), with a winding length of 50 m, have shown that omitting sub-stage wraps, can even degrade the DC performance of coils due to the short current transfer length in combination with current nonuniformity causing peak voltages in the most overloaded petals

The Costs of Judging Judges by the Numbers

This essay discredits current empirical models that are designed to “judge” or rank appellate judges, and then assesses the harms of propagating such models. First, the essay builds on the discussion of empirical models by arguing that (1) the judicial virtues that the legal empiricists set out to measure have little bearing on what actually makes for a good judge; and (2) even if they did, the empiricists’ chosen variables have not measured those virtues accurately. The essay then concludes that by generating unreliable claims about the relative quality of judges, these studies mislead both decision-makers and the public, degrade discussions of judging, and could, if taken seriously, detrimentally alter the behavior of judges themselves

Electromagnetic Performance of Sub-Size NbTi CICC's Subjected to Transverse Cyclic Loading

It was demonstrated previously that transverse cable loading due to electromagnetic forces in coils has a strong impact on the inter-strand contact resistance R/sub c/ of poloidal field (PF) cable-in-conduit conductors (CICC) for the International Thermonuclear Experimental Reactor (ITER). Continuing the study, two NbTi medium-size CICC's were subjected to cyclic loading up to 40,000 cycles in the Twente Cryogenic Press in order to simulate transversal forces on the strands and to verify their influence on the conductors' contact resistances R/sub c/ and AC loss behavior. The results are presented and compared with the data obtained on the other section of the same conductor lengths in the SULTAN test facility and on full size ITER cables tested in the cryogenic press