450 research outputs found

    Materials Handling Vehicles : Policy Framework for an Emerging Fuel Cell Market

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    © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Canadian Hydrogen and Fuel Cell Association. Open access under CC BY-NC-ND licenseThere are several challenges to wide-spread commercialisation of the technology hydrogen fuel-cell technology; including reliability and cost implications, infrastructure requirements, and safety aspects of the upcoming technology. Targeted policy initiatives are required to address two significant bottlenecks; reliability and cost constraints. Such policy measures and financial mechanisms providing incentives for manufacturers and end-users of the novel technology create an initial impetus for the introduction of the forthcoming technology into the market place. The current approach, policy mechanisms and their impacts are reviewed in the context of demonstration projects, deploying material handling equipment, involving public-private initiatives.Final Published versio

    Sustainable Hydrogen Evaluation in Logistics; SHEL

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    © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Canadian Hydrogen and Fuel Cell Association. Open access under CC BY-NC-ND licenseMaterials handling vehicles are currently powered by either electric motor based on lead-acid batteries or combustion engines employing diesel or liquefied petroleum gas. Fuel cells offer significant advantage over the competing technology. SHEL is a three-year European project involving 13 partners from six countries. The overall aim of the project is to deploy 10 fuel-cell powered forklift trucks and associated hydrogen refuelling infrastructure across 3 sites in Europe. Real time information will be gathered, and efficient procedures will be developed to reduce the time required for product certification and infrastructural build approval

    Experimental evaluation into novel, low cost, modular PEMFC stack

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    Attribution-NonCommercial-NoDerivs 3.0 Unported (CC BY-NC-ND 3.0)The Polymer Electrolyte Membrane Fuel Cell (PEMFC), despite being regarded as an ideal replacement to the internal combustion engine, is still not an economically attractive pri-mover due to a number of key challenges that have yet to be fully resolved; some of which include degradation to cell components resulting in inadequate lifetimes, specialised and costly manufacturing processes and poor gravimetric/volumetric energy densities. This paper presents a novel stack concept which removes the conventional bi polar plate (BPP), a component that is responsible for up to 80% of total stack weight and 90+% of stack volume in some designs. The removal of said component not only improves the volumetric and gravimetric energy density of the PEMFC stack but drastically reduces the cost of the stack by removing all costly manufacturing processes associated with PEMFC component machining while the functionality of the traditional BPP is still retained by the unique stack design. The stack architecture is first presented and then the characterisation of the PEMFC is shown over a wide range of operating scenarios. The experimental studies suggest that the performance of the new design is comparable to that of traditional stacks but at significantly less cost price.Final Published versio

    Numerical simulation of combined mixing and separating flow in channel filled with porous media

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    Various flow bifurcations are investigated for two dimensional combined mixing and separating geometry. These consist of two reversed channel flows interacting through a gap in the common separating wall filled with porous media of Newtonian fluids and other with unidirectional fluid flows. The Steady solutions are obtained through an unsteady finite element approach that employs a Taylor-Galerkin/pressure-correction scheme. The influence of increasing inertia on flow rates are all studied. Close agreement is attained with numerical data in the porous channels for Newtonian fluids.Peer reviewedSubmitted Versio

    Electromagnetic heating processes: analysis and simulations

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    Electromagnetic heating (EMH) processes are being increasingly used in the industrial and domestic sectors, yet they receive relatively little attention in the thermal engineering domain. Time-temperature characteristics in EMH are qualitatively different from those in conventional heating techniques due to the additional parameters (viz dielectric properties of the material, size and shape of the product and process frequency). From a unified theory perspective, a multi-purpose model has been developed in order to obtain the heating characteristics for an arbitrary processing situation. Theoretical analyses of various EMH processes in materials of various regular geometries and a range of physical properties have been undertaken. Despite the wide spread usage of microwave energy in the food engineering sector. few understand microwaves and their interactions with foods. Much of the published research is largely focussed from the view point of an electrical engineer and aimed at the oven designer. However, trial-and-error methods are usually employed when developing microwavable food products and when using microwave ovens. The presented thesis is focussed from the view-point of the thermal engineer and aimed primarily at food developers and end users. The multi-purpose model was then modified specifically for simulating the heating of food materials in a microwave oven. The validity of the commonly made assumptions was investigated; in particular the variation of dielectriC properties during the heating processes and their likely influence on the model's predictions. Experimental data available in the literature were compiled and analysed to form a set of equations for predicting the dielectric properties of various food materials. Also available correlations for thermal properties were evaluated for a selected set of experimental data of different food materials. Analyses were undertaken to demonstrate and evaluate the effects of various parameters on the heating characteristics of different food materials commonly heated/cooked in microwave ovens. A qualitative comparison of model predictions and experimental measurements is provided to validate the physical basis of the model. Findings from the model lead to a better understanding of the interactions between foods and microwaves. [...cont.

    Blunt A., Gruffudd P., May J., Ogborn M. & Pinder D., Cultural Geography in Practice

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    L’ouvrage anglo-saxon pourrait-il apporter à la définition de la géographie culturelle un doux vent de fraîcheur ? Pourrait-il enfin articuler les centres d’intérêts de la discipline aux approches plus communes de la production et de l’organisation des territoires ? C’est la question que l’on peut se poser lorsque l’on ouvre aujourd’hui un ouvrage de géographie culturelle, dont on sait la profusion contemporaine et la variété qualitative. D’entrée de jeu, l’ouvrage est présenté par ses auteur..

    Role and Important Properties of a Membrane with Its Recent Advancement in a Microbial Fuel Cell

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    Microbial fuel cells (MFC) are an emerging technology for wastewater treatment that utilizes the metabolism of microorganisms to generate electricity from the organic matter present in water directly. The principle of MFC is the same as hydrogen fuel cell and has three main components (i.e., anode, cathode, and proton exchange membrane). The membrane separates the anode and cathode chambers and keeps the anaerobic and aerobic conditions in the two chambers, respectively. This review paper describes the state-of-the-art membrane materials particularly suited for MFC and discusses the recent development to obtain robust, sustainable, and cost-effective membranes. Nafion 117, Flemion, and Hyflon are the typical commercially available membranes used in MFC. Use of nonfluorinated polymeric membrane materials such as sulfonated silicon dioxide (S-SiO2) in sulfonated polystyrene ethylene butylene polystyrene (SSEBS), sulfonated polyether ether ketone (SPEEK) and graphene oxide sulfonated polyether ether ketone (GO/SPEEK) membranes showed promising output and proved to be an alternative material to Nafion 117. There are many challenges to selecting a suitable membrane for a scaled-up MFC system so that the technology become technically and economically viable

    AI-Driven High-Precision Model for Blockage Detection in Urban Wastewater Systems

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    In artificial intelligence (AI), computer vision consists of intelligent models to interpret and recognize the visual world, similar to human vision. This technology relies on a synergy of extensive data and human expertise, meticulously structured to yield accurate results. Tackling the intricate task of locating and resolving blockages within sewer systems is a significant challenge due to their diverse nature and lack of robust technique. This research utilizes the previously introduced “S-BIRD” dataset, a collection of frames depicting sewer blockages, as the foundational training data for a deep neural network model. To enhance the model’s performance and attain optimal results, transfer learning and fine-tuning techniques are strategically implemented on the YOLOv5 architecture, using the corresponding dataset. The outcomes of the trained model exhibit a remarkable accuracy rate in sewer blockage detection, thereby boosting the reliability and efficacy of the associated robotic framework for proficient removal of various blockages. Particularly noteworthy is the achieved mean average precision (mAP) score of 96.30% at a confidence threshold of 0.5, maintaining a consistently high-performance level of 79.20% across Intersection over Union (IoU) thresholds ranging from 0.5 to 0.95. It is expected that this work contributes to advancing the applications of AI-driven solutions for modern urban sanitation systems
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