SPH analysis of inkjet droplet impact dynamics

This paper presents a novel Smoothed Particle Hydrodynamics (SPH) framework for analysis of droplet impact dynamics in a 3D inkjet printing process. Results obtained are validated against experimentally derived high-speed imaging data. The numerical framework is based on the Smoothed Particle Hydrodynamics approach of Monaghan et al [1] which has been proven to be efficient and effective for analysis of dynamic fluid flow problems involving free surface interfaces. The SPH approach has been augmented through addition of the kernel gradient correction scheme proposed by Belytschko et al [2] and stabilization terms of Marrone et el [3]. This correction provides a more accurate approximation of the boundary forces including surface tension which dominate at typical inkjet droplet lengthscales (<100 µm). Analysis is expedited through adoption of the OpenACC programming paradigm to enable GPU based computation. Numerical analyses have been validated against analytical solutions, reference macroscale problems and through comparison with experimental high speed imaging data of the inkjet printing process. The experimental setup consisted of a Fuji Dimatix SL-128 inkjet printhead jetting an acrylate based 3D printing build material onto a glass substrate. Images of a single inkjet droplet impacting onto the glass slide were captured at a rate of 100,000 frames per second, with droplet diameter assessed using a weight test approach. Qualitative comparison of the numerical and experimental results showed a good agreement, indicating that the implemented framework is effective for analysis of the fluidic aspects of the printing process. The model is able to assist in tackling manufacturing issues that can detrimentally influence the quality of manufactured parts through provision of insight into the process

Esquistos bituminosos como materia prima alternative en la fabricación de clínker de cemento Portland. Reacciones de clinkerización y caracterización del clínker

For some time the cement industry has been seeking procedures to effectively lower the higher energy costs involved in cement manufacture. Timahdit oil shale and Jerada coal waste could potentially be used as alternative raw materials to produce clinker. This study explored the possibility of applying those materials to a greener use, based on the reactivity and burnability of raw mixes containing Moroccan oil shale and coal waste. The findings showed that, irrespective of particle size, oil shale mixes delivered higher reactivity than coal waste materials, although reactivity was highest in the oil shale clinker with a particle size 70 %).La industria cementerabusca desde hace algún tiempo procedimientos que reduzcan el alto consumo de energía de la producción de cemento. La pizarra bituminosa de Timahdit (BOS) y los desechos de carbón de Jerada (CW) se pueden utilizar potencialmente como materiales alternativos en la fabricación de clinker. Este estudio se enfoca en evaluar esta posibilidad, valorizar dichos materiales y considerar un uso más ecológico para ellos. Exploramos la reactividad y la aptitud a la cocción de mezclas crudas de clínker que contienen BOS o CW. La reactividad de los crudos que contienen BOS es mejor que la de los que contienen CW, independientemente de su tamaño de partícula, siendo el que contiene BOS con un tamaño de partícula 70%

Policies on sexual expression in forensic psychiatric settings in different European countries

Background: Sexual expression by forensic psychiatric patients is poorly researched. Methods: Forensic experts representing 14 European countries were interviewed to explore the diverse ways in which sexual expression within forensic settings is handled. Results: No country had a national policy, although many had local policies or shared practices. Progressive approaches to patient sexuality were evident in nine of the countries sampled. The UK appeared the most prohibiting and excluding, its protocols apparently based on risk aversion and lack of emphasis or consideration of patients’ sexual needs. Conclusions: Uniform national policy supporting patients’ sexual expression would provide significant improvements

Enhancing the extended awareness capability of the Expeditionary Strike Group

This document describes the design, installation, and operation of an improved measurement system for the aerothermodynamic flow path states in an Allison T63-A-700 (C250-18 civilian designation). Temperature measurements for the gas generator turbine and exhaust state points were evaluated and average values were calculated. The measurement uncertainty for airflow, fuel flow, and output power has been reduced to less than 3%. State points match installation design data within 3%. The digital scanning array has improved the accuracy of the pressure measurements and added the ability to measure pressure differences over time. The added bellmouth pressure sensors provide a redundant pressure measurement that is more accurate than the dynamometer system. The gas generator turbine inlet and exhaust temperature profiles have been measured and show that the temperature profile becomes less symmetrical with increasing air and fuel flow. The measurement values for the gas generator inlet temperature have been consolidated into a single value that is about 50 degrees different from expected values. The temperature profile at the power turbine inlet shows how the hot spot at the gas generator turbine inlet is affected by the swirl produced by the power turbine stages. The time resolved fluctuations in pressure between the compressor and gas generator turbine have been measured and show that compressor discharge and gas generator turbine inlet pressures are similar.http://archive.org/details/improvederotherm109455956Ensign, United States NavyApproved for public release; distribution is unlimited

Géochimie organique de séries sédimentaires du crétacé@ (gisements de Timahdit et Tarfaya (Maroc))

POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Pedestrian Lighting, Acceptable Levels of Light: A Pilot Project

This pilot project study was intended to demonstrate that assessing the adequacy of an area’s pedestrian lighting need not be an expensive, time-consuming, or overly complicated process.Delaware Department of Transportatio