Comparison of Different Additive Manufacturing Methods Using Optimized Computed Tomography

Additive manufacturing (AM) allows for fast fabrication of three dimensional objects with the possibility of use of considerably less resources than would be the case in traditional manufacturing. AM is a fast and cost effective method which boasts the ability to produce components with a previously unachievable level of geometric complexity in end user industrial applications in areas such as the aerospace and automotive industries. However these processes currently lack reproducibility and repeatability with some ‘prints’ having a high rate requiring rework or even scrapping. It is therefore imperative that robust quality systems can be implemented such that the waste level of these processes can be eliminated or decreased. This study presents an artefact that has been optimised for characterisation using computed tomography (CT) with representative AM internal channels and structures. Furthermore the optimisation of the CT acquisition conditions for this artefact is presented in light of analysis of form, internal feature dimensions and position and material porosity

Comparison of Different Additive Manufacturing Methods Using Computed Tomography

Additive manufacturing (AM) allows for fast fabrication of three dimensional objects with the use of considerably less resources, less energy consumption and shorter supply chain than would be the case in traditional manufacturing. AM has gained significance due to its cost effective method which boasts the ability to produce components with a previously unachievable level of geometric complexity in prototyping and end user industrial applications, such as aerospace, automotive and medical industries. However these processes currently lack reproducibility and repeatability with some ‘prints’ having a high probability of requiring rework or even scrapping due to out of specification or high porosity levels, leading to failure due to structural stresses. It is therefore imperative that robust quality systems be implemented such that the waste level of these processes can be significantly decreased. This study presents an artefact that is optimised for characterisation of form using computed tomography (CT) with representative geometric dimensioning and tolerancing features and internal channels and structures comparable to cooling channels in heat exchangers. Furthermore the optimisation of the CT acquisition conditions for this artefact are presented in light of feature dimensions and form analysis. This paper investigates the accuracy and capability of CT measurements compared with reference measurements from coordinate measuring machine (CMM), as well as focus on the evaluation of different AM method

Comparison of Different Additive Manufacturing Methods Using Optimized Computed Tomography

Additive manufacturing (AM) allows for fast fabrication of three dimensional objects with the use of considerably less resources, less energy consumption and shorter supply chain than would be the case in traditional manufacturing. AM has gained significance due to its cost effective method which boasts the ability to produce components with a previously unachievable level of geometric complexity in prototyping and end user industrial applications, such as aerospace, automotive and medical industries. However these processes currently lack reproducibility and repeatability with some ‘prints’ having a high probability of requiring rework or even scrapping due to out of specification or high porosity levels, leading to failure due to structural stresses. This study presents an artefact that is optimised for characterisation of form using computed tomography (CT) with representative geometric dimensioning and tolerancing features and internal channels and structures comparable to cooling channels in heat exchangers. Furthermore the optimisation of the CT acquisition conditions for this artefact are presented in light of feature dimensions and form analysis. This poster investigates the accuracy and capability of CT measurements compared with reference measurements from coordinate measuring machine (CMM), as well as focus on the evaluation of different AM methods

Characterization of fluid flow in a microchannel with a flow disturbing step

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The flow around a flow-disturbing step in a rectangular microchannel is studied by measuring the wall shear rate along the channel, using the electrodiffusion technique and by determining the velocity field using the -PIV method. A parametric study based on the Design of Experiments (DOE) and the Response Surface Methodology (RSM) was then performed, and the effect of key design parameters on the flow characteristics was numerically investigated using CFD simulations. The computational results are in excellent agreement with the corresponding experimental ones. The CFD simulations cover both the laminar and the turbulent flow regime. It was revealed that in both flow regimes the step height has a major influence on the recirculation length. However, the Reynolds number (Re) value affects the recirculation length only in the laminar region, while the step length seems to have no significant effect compared to the Re and the step height. Finally, new correlations are proposed predicting the length of the bottom recirculation zone with reasonable accuracy and can be used as rough guidelines for the design of microdevices

R&D results on a CsI-TTGEM based photodetector

The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C4F10 gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI coated Triple-Thick-GEM (CsI-TTGEM) with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF2 radiator coupled to a 10x10 cm2 CsI-TTGEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode

Women Education in Rural India

In India, the status of the girl child has been a subject of much discussion, contro­versy, and debate. From the start, girl children are seen as burdens rather than blessings, bearers of exorbitant dowries, who will eventually move into the homes of their husbands. There are some overwhelming cultural and economic reasons why female children are not receiving the same medical, emotional, and educational attention as their male counterparts. The result is a low literacy rate among women in rural areas. There has been an increasing proportion of women, who are literate in just 20 years. Despite the improvements, there continues to be a large gap between the educational levels of men and women in rural India. The present study is focused on status, causes, and recommendations for rural women education

Simulation Study of an LWFA-based Electron Injector for AWAKE Run 2

The AWAKE experiment aims to demonstrate preservation of injected electron beam quality during acceleration in proton-driven plasma waves. The short bunch duration required to correctly load the wakefield is challenging to meet with the current electron injector system, given the space available to the beamline. An LWFA readily provides short-duration electron beams with sufficient charge from a compact design, and provides a scalable option for future electron acceleration experiments at AWAKE. Simulations of a shock-front injected LWFA demonstrate a 43 TW laser system would be sufficient to produce the required charge over a range of energies beyond 100 MeV. LWFA beams typically have high peak current and large divergence on exiting their native plasmas, and optimisation of bunch parameters before injection into the proton-driven wakefields is required. Compact beam transport solutions are discussed.Comment: Paper submitted to NIMA proceedings for the 3rd European Advanced Accelerator Concepts Workshop. 4 pages, 3 figures, 1 table Changes after revision: Figure 2: figures 2 and 3 of the previous version collated with plots of longitudinal electric field Line 45: E_0 = 96 GV/m Lines 147- 159: evaluation of beam loading made more accurate Lines 107 - 124: discussion of simulation geometry move

Introduction to Satellite Education on Quality Management

Education provides access to subject matter experts, interaction with career role models. It provides interaction with students in other schools, increases access to information instructional resources, offers opportunities for staff development/in-service training, and increase school community linkages. The rapid growth of satellite networks has generated interest by many state officials in statewide satellite networks. Rural areas are showing great interest in interactive satellite instruction as a way to resolve teacher shortages and meet rigorous graduation requirements. Televised classes permitting live teacher-student interaction via satellite communication systems, and regular telephone lines provide equity increasing quality of educational opportunity

Propagation of ELF Radiation from RS-LC System and Red Sprites in Earth-Ionosphere Waveguide

In this paper, two different mechanisms return stroke-lateral corona (RS-LC) system and red sprites which excite Earth-ionosphere waveguide have been discussed. The electric and magnetic fields from RS-LC system and red spites in the Earth-ionosphere waveguide have been calculated. It has been found that red sprites contribute to the Schumann resonances (SR) greatly as compared to the RS-LC system