An Investigation into the Effect of the Shell on SALM Processed Parts

Shell Assisted Layer Manufacturing (SALM) is a novel process for rapid prototyping/ tooling/ manufacture (RP/RT/RM) which is presently undergoing feasibility studies. SALM is based on layered manufacturing technology (LMT). Initially it develops the shell (boundaries) of a selected layer using a technique similar to fused deposition modelling (FDM). The developed shell is filled with a UV curable resin and is exposed to UV radiation for curing. This procedure is repeated until the complete part is built. This paper compares and contrasts properties of parts made using two options available with the SALM technique: building the part using a soluble shell (FDM support structure material, finally dissolved to recover the part); or using a polymer material such as ABS that is bonded with the resin whilst making the part.Mechanical Engineerin

A cellular automaton model of crystalline cellulose hydrolysis by cellulases

<p>Abstract</p> <p>Background</p> <p>Cellulose from plant biomass is an abundant, renewable material which could be a major feedstock for low emissions transport fuels such as cellulosic ethanol. Cellulase enzymes that break down cellulose into fermentable sugars are composed of different types - cellobiohydrolases I and II, endoglucanase and β-glucosidase - with separate functions. They form a complex interacting network between themselves, soluble hydrolysis product molecules, solution and solid phase substrates and inhibitors. There have been many models proposed for enzymatic saccharification however none have yet employed a cellular automaton approach, which allows important phenomena, such as enzyme crowding on the surface of solid substrates, denaturation and substrate inhibition, to be considered in the model.</p> <p>Results</p> <p>The Cellulase 4D model was developed <it>de novo </it>taking into account the size and composition of the substrate and surface-acting enzymes were ascribed behaviors based on their movements, catalytic activities and rates, affinity for, and potential for crowding of, the cellulose surface, substrates and inhibitors, and denaturation rates. A basic case modeled on literature-derived parameters obtained from <it>Trichoderma reesei </it>cellulases resulted in cellulose hydrolysis curves that closely matched curves obtained from published experimental data. Scenarios were tested in the model, which included variation of enzyme loadings, adsorption strengths of surface acting enzymes and reaction periods, and the effect on saccharide production over time was assessed. The model simulations indicated an optimal enzyme loading of between 0.5 and 2 of the base case concentrations where a balance was obtained between enzyme crowding on the cellulose crystal, and that the affinities of enzymes for the cellulose surface had a large effect on cellulose hydrolysis. In addition, improvements to the cellobiohydrolase I activity period substantially improved overall glucose production.</p> <p>Conclusions</p> <p>Cellulase 4D simulates the enzymatic hydrolysis of cellulose to glucose by surface and solution phase-acting enzymes and accounts for complex phenomena that have previously not been included in cellulose hydrolysis models. The model is intended as a tool for industry, researchers and educators alike to explore options for enzyme engineering and process development and to test hypotheses regarding cellulase mechanisms.</p

On reducing uncertainty on the Elliptical Plane modal identification method

The Elliptical Plane has been recently introduced as a modal identification method that uses an alternative plot of the receptance. The method uses the dissipated energy per cycle of vibration as a starting point. For lightly damped systems with conveniently spaced modes, it produces quite accurate results, especially when compared to the well-known method of the inverse. When represented in the Elliptical Plane, the shape of the receptance is elliptical near resonant frequencies. The modal damping factor can be determined from the angle of the ellipse’s major axis with the horizontal axis, whereas the real and imaginary parts of the modal constants can be determined from numerical curve-fitting (as in the method of the circle - Nyquist plot). However, the lack of points that can be used near the resonance (due to limitations in the frequency resolution, and effects from other modes near each resonance) and the fact that measurements are polluted by noise, bring uncertainty to the numerical curve-fitting. This paper aims at providing the first steps on the improvement of the quality of the modal identification of the receptance in the Elliptical Plane. The method and results are discussed with a multiple degree-of-freedom numerical example

Chord line force versus displacement for thin shallow arc pre-curved bimetallic strip

This is the accepted version of the following article: G D Angel, G Haritos, A Chrysanthou & V Voloshin, “Chord line force versus displacement for thin shallow arc pre-curved bimetallic strip”, Journal of Mechanical Engineering Science, Vol. 229(1): 116-124, first published online April 29, 2014, published by SAGE Publishing. All rights reserved. The version of record is available online at doi: http://dx.doi.org/10.1177/0954406214530873A pre-curved bimetallic strip that is applied with a force in an axial orientation, i.e. along its chord line, exhibits nonlinear force-displacement characteristics. For thin bimetallic strips, whereby the radius of curvature is large compared to the thickness of the strip, the non-linearity tends to be tangent related. The new theoretical formula introduced here was correlated to the results of a set of force-displacement tests, and a good overall fit of the theory to the test data was achieved. The formula put forward in this work enables the evaluation of large chord line displacements but is limited to the permissible stress limits of the material. This work can also be directly applied to thin shallow arc beams of a single material. The application of this work is in the field of bimetallic force-displacement actuators.Peer reviewe

Pharmacokinetics of rofecoxib in children

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109783/1/cptclpt2004285.pd

Comparing Health-Related Quality of Life of Cancer Patients under Chemotherapy and of Their Caregivers

Introduction. Cancer is a major disorder physically and psychologically affecting both patients and their caregivers. In this study, health-related quality of life (HRQoL) of patient-caregiver dyads during the period of chemotherapy was assessed. Material and Methods. Two hundred twenty-two cancer patient-caregiver dyads were enrolled in the study, which was conducted from October 2008 to March 2009. HRQoL was evaluated with EQ-5D. Results. The mean age of the sample was 57.4 and 48.9 for patients and caregivers, respectively. The EQ-5D descriptive system indicates that female patients more frequently experience anxiety and depression than male patients. Male and higher-education caregivers had higher VAS scores, while demographic factors did not seem to influence patients' HRQoL. Anxiety and depression of caregivers were correlated with patients' problems in self-care and usual activities. Conclusions. Quality of life is highly influenced during the period of chemotherapy for both patients and caregivers and is often under reported. Interventions that can improve HRQoL, especially in the domain of mental health for both cancer patients and their caregivers, need to be implemented

Hybrid-Aligned Nematic Liquid-Crystal Modulators Fabricated On Vlsi Circuits

A new method for fabricating analog Light modulators on VLSI devices is described. The process is fully compatible with devices fabricated by commercial VLSI foundries, and the assembly of the modulator structures requires a small number of simple processing steps. The modulators are capable of analog amplitude or phase modulation and can operate at video rates and at low voltages (2.2 V). The modulation mechanism and the process yielding the modulator structures are described. Experimental data are presented. (C) 1995 Optical Society of Americ

An analytical model for the identification of the threshold of stress intensity factor range for crack growth

The value of the stress intensity factor (SIF) range threshold (∆K_th ) for fatigue crack growth (FCG) depends highly on its experimental identification. The identification and application of ∆K_(th )are not well established as its determination depends on various factors including experimental, numerical or analytical techniques used. A new analytical model which can fit the raw FCG experimental data is proposed. The analytical model proposed is suitable to fit with a high accuracy the experimental data and capable to estimate the threshold SIF range. The comparison between the threshold SIF range identified with the model proposed and those found in literature is also discussed. The ∆K_th identified is found to be quite accurate and consistent when compared to the literature with a maximum deviation of 5.61%. The accuracy with which the analytical model is able to fit the raw data is also briefly discussed

Attribute and technology value mapping for conceptual product design phase

This is a pre-copyedited, author-produced PDF of an article accepted for publication in Journal of Mechanical Engineering Science following peer review. The final, definite version of this paper has been published in Journal of Mechanical Engineering Science, Aris Georgiou, George Haritos, Moyra Fowler, and Yasmin Imani, ‘Attribute and technology value mapping for conceptual product design phase’, Vol. 230(11): 1745-1756, May 2016, published by SAGE Publishing, available online at doi: https://doi.org/10.1177/0954406215585595. Copyright © 2016 The Author(s).The main focus of this paper is how the concept design phase of the product development process can be improved by using an objective data-driven approach in selecting a final concept design to progress further. A quantitative new test-bed ‘Product Optimisation Value Engineering’ (PROVEN) is presented to critically assess new and evolving powertrain technologies at the concept design phase. The new test-bed has the ability to define a technology value map to assess multiple technical options as a function of its attributes, whose precise values can be determined at a given cost. A mathematical model that incorporates a highly adaptable, data-driven and multi-attribute value approach to product specification and conceptual design is developed, novel to the concept design process. This creates a substantially optimised product offering to the market, reducing overall development costs while achieving customer satisfactionPeer reviewe

Proceedings of Abstracts Engineering and Computer Science Research Conference 2019

© 2019 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Note: Keynote: Fluorescence visualisation to evaluate effectiveness of personal protective equipment for infection control is © 2019 Crown copyright and so is licensed under the Open Government Licence v3.0. Under this licence users are permitted to copy, publish, distribute and transmit the Information; adapt the Information; exploit the Information commercially and non-commercially for example, by combining it with other Information, or by including it in your own product or application. Where you do any of the above you must acknowledge the source of the Information in your product or application by including or linking to any attribution statement specified by the Information Provider(s) and, where possible, provide a link to this licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/This book is the record of abstracts submitted and accepted for presentation at the Inaugural Engineering and Computer Science Research Conference held 17th April 2019 at the University of Hertfordshire, Hatfield, UK. This conference is a local event aiming at bringing together the research students, staff and eminent external guests to celebrate Engineering and Computer Science Research at the University of Hertfordshire. The ECS Research Conference aims to showcase the broad landscape of research taking place in the School of Engineering and Computer Science. The 2019 conference was articulated around three topical cross-disciplinary themes: Make and Preserve the Future; Connect the People and Cities; and Protect and Care