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Material Flows (material + flow)
Selected AbstractsValidation of Marker Material Flow in 4mm Thick Friction Stir Welded Al 2024-T351 through Computer Microtomography and dedicated Metallographic TechniquesADVANCED ENGINEERING MATERIALS, Issue 6 2006R. Zettler This study forms part of a joint three year project between the GKSS-Forschungszentrum and Airbus Deutschland titled "Effect of material flow patterns on the properties of friction stir welds in aluminium alloys for aircraft structures" -EMFASIS. The global aim of our research project is to identify how process and geometric parameters such as weld tool geometry influence the weld energy and subsequent joint properties of four friction stir welded aerospace grade aluminium alloys. The current study reports on the visualisation and displacement of a Ti powder marker material dispersed within the weld zone and investigated with the aid of X-ray computer microtomography (,CT) and dedicated metallographic techniques. [source] Material Flows in a Social Context: A Vietnamese Case Study Combining the Materials Flow Analysis and Action-in-Context FrameworksJOURNAL OF INDUSTRIAL ECOLOGY, Issue 1 2007Marieke HOBBES Summary Materials flow analysis (MFA) is one of the central achievements of industrial ecology. One direction in which one can move MFA beyond mere accounting is by putting the material flows in their social context. This "socially extended MFA" may be carried out at various levels of aggregation. In this article, specific material flows will be linked to concrete actors and mechanisms that cause these flows,using the action-in-context (AiC) framework, which contains, inter alia, both proximate and indirect actors and factors. The case study site is of Tat hamlet in Vietnam, set in a landscape of paddy fields on valley floors surrounded by steep, previously forested slopes. Out of the aggregate MFA of Tat, the study focuses on material flows associated with basic needs and sustainability. The most important actors causing these material flows are farming households, politicians, traders, and agribusiness firms,of which local politicians turned out to be pivotal. The study shows the value of combining MFA with actor-based social analysis. MFA achieves the balanced quantification of the physical system, thus helping to pinpoint key processes. Actor-based analysis adds the causal understanding of what drives these key processes, leading to improved scenarios of the future and the effective identification of target groups and instruments for policy making. [source] Materials and Energy Flow Analysis of Paper Consumption in the United Kingdom, 1987-2010JOURNAL OF INDUSTRIAL ECOLOGY, Issue 3 2001Erik Sundin Summary This article presents the results of a life-cycle materials and energy flow analysis for the pulp and paper cycle in the United Kingdom. Material flows are reconstructed for the period be-tween 1987 and 1996 for all major processes associated with the paper cycle, and system energy requirements are calculated over this period using the best available data. Attention is drawn to the import dependence of U.K. paper demand, and the significant energy requirements associated with upstream forestry processes. The historical trend analysis is then used to model possible future developments in materials and energy consumption until 2010 under a variety of assumptions about process technology improvements, wastepaper utilization rates, and changing demand trends. The results indicate that policy options to increase recycling yield some energy benefits, but these are small by comparison with the benefits to be gained by reducing consumption of paper and improving process technology. The structure of the electricity supply industry in the United Kingdom means that global energy benefits could also be achieved by increasing the contribution from imported pulp. [source] Finite-element analysis of a combined fine-blanking and extrusion processINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2006P. F. Zheng Abstract This paper presents the characteristics of the combined fine-blanking and extrusion process and gives a detailed analysis of the process with the finite-element method. To carry out the simulation step by step and avoid the tendency to diverge in the calculations, the remeshing, tracing and golden section methods were developed and introduced into the finite-element program. Different boundary conditions were used in the simulation; the mesh distortion, field of material flow, and the stress and strain distributions were obtained. From the simulated results, the deformation characteristics under different boundary conditions were revealed. An experiment was also carried out to verify the simulated results. A large strain analysis technique was chosen to determine the effective strain distribution based on the experiment. The effective strain distributions from the simulation are in accordance with the effective strain distributions and the hardness distributions from the experiment. Copyright © 2005 John Wiley & Sons, Ltd. [source] Application of a Bayesian Approach to the Tomographic Analysis of Hopper FlowPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 4 2005Krzysztof Grudzien Abstract This paper presents a new approach to the analysis of data on powder flow from electrical capacitance tomography (ECT) using probability modelling and Bayesian statistics. The methodology is illustrated for powder flow in a hopper. The purpose, and special features, of this approach is that ,high-level' statistical Bayesian modelling combined with a Markov chain Monte Carlo (MCMC) sampling algorithm allows direct estimation of control parameters of industrial processes in contrast to usually applied ,low-level', pixel-based methods of data analysis. This enables reliable recognition of key process features in a quantitative manner. The main difficulty when investigating hopper flow with ECT is due to the need to measure small differences in particle packing density. The MCMC protocol enables more robust identification of the responses of such complex systems. This paper demonstrates the feasibility of the approach for a simple case of particulate material flow during discharging of a hopper. It is concluded that these approaches can offer significant advantages for the analysis and control of some industrial powder and other multi-phase flow processes. [source] Material Flow Networks as a Means of Optimizing Production SystemsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 4 2010H. Lambrecht Abstract Material flow networks are a specific technique for material flow analysis. Software tools based on this method have been used by many companies to analyze and improve complex production systems. While their intuitive modeling approach strongly enhances the identification of optimization potentials, automatic model optimization is not yet possible. The KOMSA project has closed this important methodological and instrumental gap. This article presents the developed prototype of a material flow-based optimization tool. We provide numerical results on the convergence of the implemented optimization algorithms. The added value of integrating optimization with material flow analysis is illustrated by applying the software tool to a real optimization problem from the waste industry. [source] The seismic anomaly beneath Iceland extends down to the mantle transition zone and no deeperGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2000G. R. Foulger A 3-D teleseismic tomography image of the upper mantle beneath Iceland of unprecedented resolution reveals a subvertical low wave speed anomaly that is cylindrical in the upper 250 km but tabular below this. Such a morphological transition is expected towards the bottom of a buoyant upwelling. Our observations thus suggest that magmatism at the Iceland hotspot is fed by flow rising from the mantle transition zone. This result contributes to the ongoing debate about whether the upper and lower mantles convect separately or as one. The image also suggests that material flows outwards from Iceland along the Reykjanes Ridge in the upper 200 km, but is blocked in the upper 150 km beneath the Tjornes Fracture Zone. This provides direct observational support for the theory that fracture zones dam lateral flow along ridges. [source] Multi-material incompressible flow simulation using the moment-of-fluid method,INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 8 2010Samuel P. Schofield Abstract This paper compares the numerical performance of the moment-of-fluid (MOF) interface reconstruction technique with Youngs, LVIRA, power diagram (PD), and Swartz interface reconstruction techniques in the context of a volume-of-fluid (VOF) based finite element projection method for the numerical simulation of variable-density incompressible viscous flows. In pure advection tests with multiple materials MOF shows dramatic improvements in accuracy compared with the other methods. In incompressible flows where density differences determine the flow evolution, all the methods perform similarly for two material flows on structured grids. On unstructured grids, the second-order MOF, LVIRA, and Swartz methods perform similarly and show improvement over the first-order Youngs' and PD methods. For flow simulations with more than two materials, MOF shows increased accuracy in interface positions on coarse meshes. In most cases, the convergence and accuracy of the computed flow solution was not strongly affected by interface reconstruction method. Published in 2009 by John Wiley & Sons, Ltd. [source] Material Flow Indicators in the Czech Republic in Light of the Accession to the European UnionJOURNAL OF INDUSTRIAL ECOLOGY, Issue 4 2010Jan Kovanda Summary This article deals with the economy-wide material flows in the Czech Republic in 1990,2006. It presents in brief the overall trends of the material flow indicators in 1990,2002. The major part of the article is focused on the years 2002,2006, which immediately preceded and followed the accession of the Czech Republic to the European Union in 2004. It is shown that this accession had quite a significant impact on the volume and character of the material flows of the Czech Republic. The accession was beneficial from an economic point of view, as it allowed for an increased supply of materials needed for economic growth. Furthermore, it was accompanied by an improvement in the efficiency of material transformation into economic output. From an environmental and broader sustainability point of view, however, this accession brought about some controversial outcomes. There was a significant increase in the net export of environmental pressure, on one hand, and an increase in net additions to the physical stock of the economy, on the other. Although the former is controversial from the viewpoint of equity in sharing area and resources, the latter places an additional burden on future generations because all physical stocks will turn into waste and emissions at some point, when their life span expires. [source] The Direct Material Inputs into Singapore's DevelopmentJOURNAL OF INDUSTRIAL ECOLOGY, Issue 2 2007Niels B. Schulz Because human population and socioeconomic activity are both increasingly concentrated in cities, an improved understanding of the environmental consequences of urbanization is needed. A 41-year annual time series of direct material flows was compiled for Singapore, representing a case of fast, export-driven industrialization. Results show that the spectacular economic growth of Singapore by a factor of 20 was associated with a similar expansion of domestic material consumption (DMC). DMC remained closely coupled to economic activity, increasing from below 4 tonnes per capita annually in 1962 to more than 50 tonnes annually in 2000. Despite economic structural changes and a growing service sector, no significant improvements in overall material productivity have been observed. [source] Material Flows in a Social Context: A Vietnamese Case Study Combining the Materials Flow Analysis and Action-in-Context FrameworksJOURNAL OF INDUSTRIAL ECOLOGY, Issue 1 2007Marieke HOBBES Summary Materials flow analysis (MFA) is one of the central achievements of industrial ecology. One direction in which one can move MFA beyond mere accounting is by putting the material flows in their social context. This "socially extended MFA" may be carried out at various levels of aggregation. In this article, specific material flows will be linked to concrete actors and mechanisms that cause these flows,using the action-in-context (AiC) framework, which contains, inter alia, both proximate and indirect actors and factors. The case study site is of Tat hamlet in Vietnam, set in a landscape of paddy fields on valley floors surrounded by steep, previously forested slopes. Out of the aggregate MFA of Tat, the study focuses on material flows associated with basic needs and sustainability. The most important actors causing these material flows are farming households, politicians, traders, and agribusiness firms,of which local politicians turned out to be pivotal. The study shows the value of combining MFA with actor-based social analysis. MFA achieves the balanced quantification of the physical system, thus helping to pinpoint key processes. Actor-based analysis adds the causal understanding of what drives these key processes, leading to improved scenarios of the future and the effective identification of target groups and instruments for policy making. [source] 132 Parasites and Phytoplankton, with a Special Emphasis on Dinoflagellate InfectionsJOURNAL OF PHYCOLOGY, Issue 2003M. G. Park Eukaryotic parasites are believed to play important roles in phytoplankton ecology and particularly in bloom dynamics of red-tide dinoflagellates. Apart from the prokaryotic parasites such as viruses and bacteria, certain flagellates and fungi have received some degree of attention as eukaryotic parasites of phytoplankton. Our understanding of fungal parasites is largely based on studies for freshwater diatoms and dinoflagellates, although fungal infections are known for some marine phytoplankton, including diatoms. By comparison, the dinoflagellate genus Amoebophrya and the newly described Perkinsozoa Pavilucifera infectans are widely distributed in coastal waters of the world and are well known as eukaryotic parasites of dinoflagellates. Recent work indicates that these parasites have significant impacts on the ecophysiology and behavior of dinoflagellate hosts. Thus, the ecological roles of Amoebophrya spp. and Pavilucifera infectans should be carefully considered in developing concepts about plankton dynamics and material flows in marine food webs. [source] Industrial ecology, life cycles, supply chains: differences and interrelationsBUSINESS STRATEGY AND THE ENVIRONMENT, Issue 5 2004Stefan Seuring Within recent years, various concepts have arisen in environmental management that directly address the flow of material (and information) along life cycles or supply chains and thereby relate to inter-organizational management aspects. These include industrial ecology (IE), life-cycle management, closed-loop supply chains, integrated chain management and green/environmental or sustainable supply chain management. It is not clear how these concepts relate to each other and whether or how they are different. Starting with sustainable development three criteria are identified that allow the comparison of the four concepts. Building on definitions the concepts are discussed and analysed using the three criteria while also identifying a distinctive feature of each approach. The criteria reveal that the concepts take a specific approach to study material flows in their particular system boundaries. This also relates to the time frame usually applied within the concept as well as the relevant actor network taken into account. Beyond these differences, it arises that the concepts have their strengths on different levels, which leads to a framework for the interrelation of the concepts. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment. [source] | ||||||||||||||||