Material flow

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Data Reconciliation under Fuzzy Constraints in Material Flow Analysis

Data Reconciliation under Fuzzy Constraints in Material Flow Analysis

Keywords : Material flow analysis, data reconcilia- tion, least squares, fuzzy constraints 1. Introduction Material flow analysis consists in calculating the quantities of a certain product transiting a network of local entities referred to as processes, considering input and output flows and including the presence of material stocks. The unknowns to be determined are the values of the flows and stocks. The basic principle that provides constraints on the flows is that what goes into a process must come out, up to the variations of stock. Flows and stocks must be balanced, through a set of linear equations. The mass-balance equation relative to a process with n flows in, k flows out and a stock level s is written:
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Material flow analysis applied to rare earth elements in Europe

Material flow analysis applied to rare earth elements in Europe

This paper explores flows and stocks, at the scale of the European Union, of certain rare earth elements (REEs; Pr, Nd, Eu, Tb, Dy and Y) which are associated with products that are important for the decarbonisation of the energy sector and that also have strong recycling potential. Material flow analyses were performed considering the various steps along the value chain (separation of rare earth oxides, manufacture of products, etc.) and including the lithosphere as a potential stock (potential geological resources). Results provide estimates of flows of rare earths into use, in-use stocks and waste streams. Flows into use of, e.g., Tb in fluorescent lamp phosphors, Nd and Dy in permanent magnets and Nd in battery applications were estimated, for selected reference year 2010, as 35, 1230, 230 and 120 tons respectively. The proposed Sankey diagrams illustrate the strong imbalance of flows of permanent magnet REEs along the value chain, with Europe relying largely on the import of finished products (magnets and applications). It is estimated that around 2020, the amounts of Tb in fluorescent lamps and Nd in permanent magnets recycled each year in Europe, could be on the order of 10 tons for Tb and between 170 and 230 tons for Nd.
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Energy and Material Flow Analysis of Binder-jetting Additive Manufacturing Processes

Energy and Material Flow Analysis of Binder-jetting Additive Manufacturing Processes

* Corresponding author. Tel.: +1-514-398-2523; fax: +1-514-398-7365. E-mail address: yaoyao.zhao@mcgill.ca Abstract Manufacturing, where great amount of energy and materials are being consumed, should take response to have cleaner production and to improve its sustainability. Additive manufacturing (AM) technology shows potential to reduce environment impact as a more sustainable manufacturing method; however, the lack of well documented energy consumption and material flow data limits the development of Life-Cycle Inventory (LCI) analysis of AM technology. This paper presents an energy and material consumption model of Binder-Jetting (BJ) process. A Unit-Process (UP) level model is created and validated by experimental data to provide LCI data for further Life-Cycle Analysis (LCA) of BJ additive manufacturing processes. The accurate process model provides a tool to industry to understand the energy consumption and material efficiency aspect of the binder-jetting process and to allow comparisons with traditional processes.
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Effects Of Thermal Exchange On Material Flow During Steel Thixoextrusion Process

Effects Of Thermal Exchange On Material Flow During Steel Thixoextrusion Process

Several parts extruded under various process conditions are shown in figure 6; with a relative low punch speed and a cold die, a critical initial billet temperature around 1437°C was found. A heterogeneous flow was observed with initial billet temperature above 1437°C. Bad surfaces with wrenching and cracking which revealed a liquid/solid phase separation were observed on parts extruded with a higher initial billet temperature. This separation phenomenon was also presented in work [8] for other steel grades. Meanwhile, when a warm die and Ceraspray© layer were employed for the extrusion of a billet at 1445°C, a correct shape was obtained, which meant that the critical temperature was moved to a higher value. The reason could be due to less heat loss during extrusion which made the liquid distribution and material morphology more uniform in the cross section, which resulted in a homogeneous material flow.
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Well-posedness of a non-local model for material flow on conveyor belts

Well-posedness of a non-local model for material flow on conveyor belts

In this paper, we focus on finite volume approximation schemes to solve a non-local material flow model in two space dimensions. Based on the numerical discretisation with dimensional splitting, we prove the convergence of the approximate solutions, where the main difficulty arises in the treatment of the discontinuity occurring in the flux function. In particular, we compare a Roe-type scheme to the well-established Lax-Friedrichs method and provide a numerical study highlighting the benefits of the Roe discretisation. Besides, we also prove the L 1 -Lipschitz continuous dependence on the initial datum, ensuring the uniqueness of the solution.
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Material flow analysis applied to rare earth elements in Europe

Material flow analysis applied to rare earth elements in Europe

Abstract This paper explores flows and stocks, at the scale of the European Union, of certain rare earth elements (REEs; Pr, Nd, Eu, Tb, Dy and Y) which are associated with products that are important for the decarbonisation of the energy sector and that also have strong recycling potential. Material flow analyses were performed considering the various steps along the value chain (separation of rare earth oxides, manufacture of products, etc.) and including the lithosphere as a potential stock (potential geological resources). Results provide estimates of flows of rare earths into use, in-use stocks and waste streams. Flows into use of, e.g., Tb in fluorescent lamp phosphors, Nd and Dy in permanent magnets and Nd in battery applications were estimated, for selected reference year 2010, as 35, 1230, 230 and 120 tons respectively. The proposed Sankey diagrams illustrate the strong imbalance of flows of permanent magnet REEs along the value chain, with Europe relying largely on the import of finished products (magnets and applications). It is estimated that around 2020, the amounts of Tb in fluorescent lamps and Nd in permanent magnets recycled each year in Europe, could be on the order of 10 tons for Tb and between 170 and 230 tons for Nd.
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A fuzzy constraint-based approach to data reconciliation in material flow analysis

A fuzzy constraint-based approach to data reconciliation in material flow analysis

Data reconciliation has been defined as “a technique to optimally adjust mea- sured process data so that they are consistent with known constraints” by Kelly (2004). According to Crowe (1996), such adjustment consists in a “constrained minimization problem that is usually one of constrained least squares”; see also (Narasimhan and Jordache 2000). Ayres and Kneese (1969) extended the appli- cation of MFA to national economies while Baccini and Brunner (1991) used it to study the metabolism of the anthroposphere, i.e., that portion of the environment that is made or modified by humans for use in human activities and human habi- tats. Material flow analysis has become an important tool in the field of industrial ecology, e.g. (Frosch and Gallopoulos 1989). More recently, researchers have applied MFA to study the global flows and stocks of metals, e.g., Graedel et al. (2004), Bon- nin et al. (2013). Some have generalized material flow analysis to several periods of time via a dynamic approach (Bai et al. 2006). Data reconciliation software are now available such as STAN (Brunner and Rechberger 2004) or BILCO (Durance et al. 2004).
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Numerical modeling of material flow with an internal length

Numerical modeling of material flow with an internal length

In this paper we propose a new numerical method to study material flow with an internal length. The finite element method with Lagrangian interpolation points (FEMLIP) is used for its capability to model large deformation processes for any type of materials. It is widely accepted in the litterature that fresh concrete rheology is very well estimated by Bigham model in the classical continuum approach. Nevertheless in most cases the form size and the distance between reinforced bars are about few times greater than aggregate size itself. This means that the microstructure has a non negligible effect on the flow (aggregate rotation independent of material rotation + boundary layer effect) and that it must be taken into account to get a good estimation of the filling capability of the material. We propose to use a Cosserat continuum with a Bingham law to tackle this work.
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Exploring material flow in friction stir welding : tool eccentricity and formation of banded structures

Exploring material flow in friction stir welding : tool eccentricity and formation of banded structures

rings in the transverse cross-section of the nugget, the formation of striations in the longitudinal sections and to a lesser extent, the distribution of typical oxide patterns in different sections of the weld [ 3 , 4 ]. The contribution of the material flow patterns around the moving tool on the formation of different banded structures of the weld nugget has been proposed. Investigations of flow patterns involve deductive conclusions from post mortem specimens by materializing tracer distribution in the weld or by tool piece frozen experiments [ 5 ]. Though tracer techniques suffer from possible discontinuities generated in material flow by their presence, they still offer the best possible channel to study material flow. For example, Colligan et al. [ 6 ] used the steel shot tracer technique in conjunction with a screw threaded pin and concluded limited stirring of the surface material and extrusion of the other materials on the retreating side of the nugget. Lorrain et al. [ 7 ] made welds using two different tool profiles and copper foils as material marker. Zettler et al. [ 2 ] used Ti powder markers for different aluminium alloys and investigated material flow by using different tool geometries. They showed a good correlation between the feed rate per rotation and band spacing whatever the tool geometry, though significant temperature field differences could be found between different tool geometries. In fact, the published literature suggests that striations arise from separation of the material flow pulled in to the stir zone from either side of the joint. From tracer techniques, the flow patterns are visualized as shearing from the advancing side followed by the material flow from the retreating side in far field of the pin. Thus, in the nearest flow field, closest to the pin, the material originates from the advancing side and is forced to flow to the other side of the joint. Material from the retreating side enters the stir zone as a separate entity
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Energy and material flow modelling of additive manufacturing processes

Energy and material flow modelling of additive manufacturing processes

Energy and material flow modelling of additive manufacturing processes Additive manufacturing processes allow fabrication of 3 dimensional complex parts. Due to the exact amount of material used during the manufacturing step, these new manufacturing processes offer great opportunities for sustainable manufacturing. However, existing studies on these processes focus mainly on energy consumption and information about resources consumptions and waste flows are still lacking. This study aims to quantify with accuracy inventory data of additive manufacturing processes during the manufacturing step of the life-cycle of a products. In order to accurately assess the environmental impact of a product, a generic method for acquisitions and characterizations of inventory data for parts made by additive manufacturing processes is proposed. This methodology not only focuses on the electrical energy consumption but also on material consumption. This paper also describes the development of a parametric process model, which provide to an operator, an accurate estimations of the environmental performances of fused deposition modeling process.
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Microstructure Evolution and Material Flow of Steel in Semi-solid Forming Process

Microstructure Evolution and Material Flow of Steel in Semi-solid Forming Process

* Corresponding author: E-mail address: guochao.gu@gmail.com; Tel.: +33 03 87 37 54 30 Abstract The present study aims to identify and characterize the development of microstructure and deformation characteristics of steel grades in semi-solid state which is affected by the change in morphologies of microstructure at high temperature. Thixoextrusion tests with different combinations of forming temperature and forming speed were performed. It was identified that several process parameters, such as initial billet and die temperatures or forming speed, affect thermal exchanges thereby influencing the microstructure evolution and material flow. Furthermore, 2D and 3D microstructure characterization was performed on the same sample which was partial remelted and quenched. Reconstructed 3D images were compared with the ones obtained with a Scanning Electron Microscope and an Energy Dispersive Spectrometry system. The good agreement between 2D SEM observations and 3D X-ray microtomography results makes these two techniques efficient to characterize steels in the semi-solid state.
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Understanding the material flow path of friction stir welding process using unthreaded tools

Understanding the material flow path of friction stir welding process using unthreaded tools

The present study aims at checking if the results observed using threaded pins can be transferred to FSW experiments using smooth pins. Few studies in literature ( Elangovan and Balasubramanian, 2007; Fratini et al., 2006; Prado et al., 2001; Zhao et al., 2005 ) were interested in material flow using unthreaded tools. Analysing material flow using unthreaded tools is of great interest for two main reasons. First, experiments using smooth tools can be directly used for the validation of a numerical model in which threads are difficult to represent. The interest of such numerical models to sim- ulate FSW processing is clear and has been demonstrated by many literature works. Numerical simulations have been widely used to obtain temperature and mechanical fields ( Schmidt and Hattel, 2005; Zhang and Zhang, 2008; Bastier et al., 2008; Fourment and Guerdoux, 2008 ). They provide a better understanding of the flow and heating mechanisms of FSW depending on the tool profiles, rotation speed, velocity speed, axial force ( Colegrove and Shercliff, 2006; Zhang and Zhang, 2009b ) in order to optimize the FSW pro- cess. Second, initially threaded tool becomes rapidly unthreaded when used for high melting point alloys such as steels and for rein- forced aluminium alloys because of the strong tool wear ( Prado et al., 2001, 2003 ). In this work, welds were made using two different tool profiles and copper foils as material marker (MM). Experimen- tal observations are presented for different copper foil orientations and aluminium sheet cuts. The experimental procedure is firstly detailed and then the results are illustrated and discussed. We show the keyrole of the product of the plunge force and the rotational speed on the size of the shoulder dominated zone. Material flow with unthreaded tool was found to have the same features as mate- rial flow using classical threaded tools: material is deposited in the advancing side (AS) in the upper part of the weld and in the retreat- ing side (RS) in the lower part of the weld; a rotating layer appears around the pin. However, the analysis revealed a too low vertical
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Development and validation of a dynamic material flow analysis model for French copper cycle

Development and validation of a dynamic material flow analysis model for French copper cycle

a Laboratoire de Génie Chimique, LGC UMR CNRS 5503 ENSIACET INPT, 4 allée Emile Monso, BP 84234, 31432 Toulouse Cedex 4, France b Bureau de Recherche Géologique et Minière, 3 avenue Claude-Guillemin, BP 36009, 45060 Orléans Cedex 2, France ABSTRACT This study performs a quantitative description of the copper life cycle at the scale of France from 2000 to 2009 with special focus on waste streams. The approach is based on substance flow analysis and includes data reconciliation. The mode! takes into account the relationships between economic system, resource consumption, product man­ ufacturing, waste generation and pollution, thus broadening the traditional scope of process systems engineering. The more important results concern waste management since France exports most of its col!ected copper wastes because there is no industry for recycling low-grade scrap. The paper shows the interest of using substance flow analysis methodology coupled with data reconciliation to obtain a precise cartography of a substance flow inside a large area. Indeed, statistic data from institutional organisms and industries may vary from one source to the other, and the utilization of the redundancy of information is an efficient tool for obtaining more precise data. Moreover, the dynamic analysis allows modeUing the stock evolution with more accuracy than in previous studies. FinaUy, the results are compared with existing values for other countries or continents, and some perspectives concerning the use of copper in France are given.
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Downscaling material flow analysis: the case of the cereals supply chain in France

Downscaling material flow analysis: the case of the cereals supply chain in France

d Artelia Eau et Environnement, Echirolles, France Abstract The spatial reconstruction of the production, trade, transformation and consumption flows of a spe- cific material, can become an important decision-help tool for improving resource management and for studying environmental pressures from the producer’s to the consumer’s viewpoint. One of the obstacles preventing its actual use in the decision-making process is that building such studies at var- ious geographical scales proves to be costly both in time and manpower. In this article, we propose a semi-automatic methodology to overcome this issue: we describe our multi-scalar model and its data-reconciliation component and apply it to cereals flows. Namely, using official databases (Insee, Agreste, FranceAgriMer, SitraM) as well as corporate sources, we reconstructed the supply chain flows of the 22 French regions as well as the flows of four nested territories: France, the Rhˆone-Alpes r´egion, the Is`ere d´epartement and the territory of the SCOT of Grenoble. We display the results using Sankey diagrams and discuss the intervals of confidence of the model’s outputs. We conclude on the perspec- tives of coupling this model with economic, social and environmental aspects that would provide key information to decision-makers.
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Material acquisition using deep learning

Material acquisition using deep learning

A selection of results from our one image method on real-world photographs. In each image pair, the left image is a photograph of a surface, and the right image is a re- rendering with environment lighting of the material solved from that image. This poster is based on my thesis work 2, 3 in which I present a number of

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Carbazole-based material: synthesis, characterization, and application as hole transporting material in perovskite solar cells

Carbazole-based material: synthesis, characterization, and application as hole transporting material in perovskite solar cells

9 3. Conclusion In summary, novel carbazole-based oligomers were synthetized, characterized, and applied as hole transporting material in perovskite photovoltaic devices. The thermal, morphological, optical and electrochemical characterizations have shown that the PCz1 oligomer material is suitable for the role of HTM. Initial photovoltaic measurements gave a PCE of 16.84 % which increased over 6 weeks to reach a value of 18.04 %. This PCE is superior to the PCE of the benchmark Spiro-OMeTAD cell. Moreover, the former has been shown much more stable than the latter. Current study is being conducted to optimize the synthesis of this family of molecules. More compounds of this family will be prepared in order to better understand the molecular structure/photovoltaic performance relationship of this series of carbazole derivatives.
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HgTe, the Most Tunable Colloidal Material: from the Strong Confinement Regime to THz Material

HgTe, the Most Tunable Colloidal Material: from the Strong Confinement Regime to THz Material

ABSTRACT HgTe nanocrystals are extremely interesting materials to obtain a highly tunable absorption spectrum in the infrared range. Here, we discuss the two extreme cases of strongly confined and barely confined HgTe nanocrystals. We discuss the synthesis and optoelectronic properties of HgTe 2D nanoplatelets where the confinement energy can be as large as 1.5 eV. This material presents enhanced (mostly narrower) light emitting properties compared to spherical nanocrystals emitting at the same wavelength. Moreover, absorption spectra, majority carriers and time response can be tuned by carefully choosing the surface chemistry and applying a well-chosen gate bias. HgTe can also be used to explore the effect of vanishing confinement and to obtain quasi bulk properties with tunable absorption in the THz, up to 150 µm.
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Bridge : information as material for design

Bridge : information as material for design

One of the areas in the voxel information where the wind was strong, and light and the water movement was weak, (which was color coded green in the previous process), was reg[r]

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Archival material and site investigations

Archival material and site investigations

Archival material and site investigations Legget, R. F.; Burn, K. N. https://publications-cnrc.canada.ca/fra/droits L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

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LATENITE: hygrothermal material property database

LATENITE: hygrothermal material property database

Archives des publications du CNRC Access and use of this website and the material on it are subject to the Terms and Conditions set forth at LATENITE: hygrothermal material property database Karagiozis, Achilles; Salonvaara, Mikael; Kumaran, Kumar

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