Achieving Control of Coating Process in your Foundry

Achieving control of coating thickness in foundry moulds is needed in order to guarantee uniform properties of the mould but also to achieve control of drying time. Since drying time of water based coatings is heavily dependent on the amount of water present in the coating layer, a stable coating process is prerequisite for a stable drying process. In this study, we analyse the effect of different variables on the coating layer properties. We start by considering four critical variables identified in a previous study such as sand compaction, coating density, dipping time and gravity and then we add centre points to the original experimental plans to identify possible non-linear effects and variation in process stability. Finally, we investigate the relation between coating penetration (a variable that is relatively simple to measure in production) and other coating layer thickness properties (relevant for the drying process design). Correlations are found and equations are provided. In particular it is found that water thickness can be directly correlated to penetration with a simple linear equation and without the need to account for other variables

Thermohydraulic Behaviour of HeII in Stratified Co-Current Two-Phase Flow at High Vapor Velocities

Recent experiments conducted with a co-current flow of saturated superfluid helium at CEA-Grenoble have shown a transition from stratified two phase flow to droplet mist flow at high vapor velocities. The two phase co-current stratified flow was circulated through a 40 mm inner diameter, 10 m long tube, with a slope ranging between 0 and 1.4%. Mass flow rates and temperatures ranged between 1 and 7 g/s, 1.8 and 2 K respectively. These various conditions allowed a comparison of the flow behavior for same void fraction but different vapor mass flows. Some evidences of atomization without any transition from stratified to annular flow are given

Optical Investigations of HeII Two Phase Flow

The LHC development program relies on cryogenic tests of prototype and model magnets. This vigorous program is pursued in a dedicated test facility based on several vertical cryostats working at superfluid helium temperatures. The performance of the facility is detailed. Goals and test equipment for currently performed studies are reviewed: quench analysis and magnet protection studies, measurement of the field quality, test of ancillary electrical equipment like diodes and busbars. The paper covers the equipment available for tests of prototypes and some special series of LHC magnets to come

Administrator Perceptions of the Teacher Evaluation Process and Professional Development Programming in New Jersey Independent Schools

This study examines administrator perceptions of the teacher evaluation process and professional development programming in New Jersey independent schools. Despite the contentious topic of teacher evaluation within the national landscape today, there is currently little research available concerning administrator perceptions of teacher evaluation and professional development within independent schools. In this study, I ask a) What teacher evaluation processes or tools are being used in the independent schools in the state of New Jersey? b) What types of professional development programs are provided for teachers in these schools? and c) How do independent school administrators perceive the relationship between the teacher evaluation system and the professional development programs? This explanatory sequential mixed methods study examined data from New Jersey independent school administrators, including surveys (N = 25) and interviews (N = 6). Results show a) New Jersey independent school administrators perceive the evaluation process has an above-average impact on teacher professional growth goals and school improvement goals; b) oftentimes, administrators allow teachers to tailor their own professional development goals; c) majority of the administrators utilize either the Danielson model or a school-created model for teacher evaluation; and d) administrators view the teacher evaluation process as a tool to foster growth in teachers and ensure teachers are mission-focused, but they are averse to using rating scales and tying evaluation to performance. The findings of this study suggest there is great value in the teacher evaluation process as long as it is grounded in professional growth, reflection, and teaching excellence