| 1. |
- Mellin, Pelle, 1985-, et al.
(författare)
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Nano-sized by-products from metal 3D printing, composite manufacturing and fabric production
- 2016
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Ingår i: Journal of Cleaner Production. - Sweden : Elsevier. - 0959-6526 .- 1879-1786. ; 139, s. 1224-1233
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Tidskriftsartikel (refereegranskat)abstract
- Recently, the health and environmental perspective of nano-materials has gained attention. Most previous work focused on Engineered Nanoparticles (ENP). This paper examines some recently introduced production routes in terms of generated nano-sized by-products. A discussion on the hazards of emitting such particles and fibers is included. Fine by-products were found in recycled metal powder after 3D printing by Selective Laser Melting (SLM). The process somehow generated small round metal particles (~1e2 mm) that are possibly carcinogenic and respirable, but not small enough to enter by skin-absorption. With preventive measures like closed handling and masks, any health related effects can be prevented. The composite manufacturing in particular generated ceramic and carbonaceous particles that are very small and respirable but do not appear to be intrinsically toxic. The smallest features in agglomerates were about 30 nm. Small particles and fibers that were not attached in agglomerates were found in a wide range of sizes, from 1 μm and upwards. Preventive measures like closed handling and masks are strongly recommended. In contrast, the more traditional production route of fabric production is investigated. Here, brushing residue and recycled wool from fabric production contained few nano-sized by-products.
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| 2. |
- Kurdve, Martin, et al.
(författare)
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Waste flow mapping to improve sustainability of waste management : A case study approach
- 2015
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 98, s. 304-315
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Tidskriftsartikel (refereegranskat)abstract
- Innovative, resource-efficient solutions and effective waste management systems capture value in business and contribute to sustainability. However, due to scattered waste management responsibilities in the vehicle industry and the orientation of operations management and lean tools, which mostly focus on lead-time and labour-time improvements, the requirement of a collaborative method to include material waste efficiency in operational development is identified. The main purpose of this research is to study how operations management and environmental management can be integrated on an operational level and include the waste management supply chain. Based on a literature review of environmental and operational improvement tools and principles, the gaps and needs in current practice were identified. A large case study implementing a waste flow mapping (WFM) method on a set of manufacturing sites revealed potentials in terms of reducing material losses and inefficiencies in the handling of materials and waste. Finally, the integrated WFM method was analysed with respect to the gaps and needs identified in the existing body of tools for operational and environmental improvement. The method combines lean manufacturing tools, such as value stream mapping with cleaner production and material flow cost accounting strategies. The empirical data showed that the WFM method is adequate for current state analysis of waste material efficiency potentials, especially when multiple organisations are involved. However, further development and specific methods are needed such as, for example, logistics inefficiencies, root cause analysis, implementation guidelines for best practice and systems for performance monitoring of actors.
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| 3. |
- Shahbazi, Sasha, et al.
(författare)
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Material Efficiency Measurement: Empirical Investigation of Manufacturing Industry
- 2017
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Ingår i: Procedia Manufacturing. - : Elsevier BV. - 2351-9789. ; 8, s. 112-120, s. 112-120
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Tidskriftsartikel (refereegranskat)abstract
- Improving material efficiency contributes to reduce the volume of industrial waste as well as resource consumption. However, less has been published addressing on what to measure for material efficiency in a manufacturing company. This paper presents the current practice of material efficiency performance indicators in a manufacturing context through a bottom-up approach. In addition to literature review, the empirical data was collected via a multiple case study at seven global manufacturing companies located in Sweden. The results show that existing material efficiency indicators are limited and are mainly measured as a cost or quality parameter rather than environment. The limited number of measurements relates to the fact that material efficiency is not considered as a central business in manufacturing companies and is managed by environmental department with limited correlation to operation. Additionally, these measurements do not aim to reduce waste volume or improve homogeneity of generated waste.
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| 4. |
- Jönsson, M., et al.
(författare)
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Bacteria counting with impedance spectroscopy in a micro probe station
- 2006
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 110:20, s. 10165-10169
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Tidskriftsartikel (refereegranskat)abstract
- A method to quantify the density of viable biological cells in suspensions is presented. The method is implemented by low-frequency impedance spectroscopy and based on the finding that immobilized ions are released to move freely in the surrounding suspension when viable Escherichia coli cells are killed by a heat shock. The presented results show that an amount of ions corresponding to ∼2 × 108 unit charges are released per viable bacterium killed. A micro probe station with coplanar Ti electrodes was electrically characterized and used as a measuring unit for the impedance spectroscopy recordings. This unit is compatible with common microfabrication techniques and should enable the presented method to be employed using a flow-cell device for viable bacteria counting in miniaturized on-line monitoring systems.
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| 5. |
- Landström, Anna, et al.
(författare)
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Present state analysis of business performance measurement systems in large manufacturing companies
- 2016
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Ingår i: PMA Conference 2016 PMA2016. - Edinburgh, United Kingdom. ; , s. 26-29
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Konferensbidrag (refereegranskat)abstract
- The purpose of this article is to empirically investigate the present state of the performance measurement systems (PMS) at 7 sites of 6 different large Swedish manufacturing companies. The methodology has both a bottom-up and a top-down perspective. Important findings are that the PMSs are very similar in how they function but differ a lot in what is measured.
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| 6. |
- Liu, G., et al.
(författare)
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Numerical analysis of inner heating tube position for improving solid-phase transition in a shell-and-tube heat accumulator
- 2023
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Ingår i: Alexandria Engineering Journal. - : Elsevier B.V.. - 1110-0168 .- 2090-2670. ; 65, s. 771-784
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Tidskriftsartikel (refereegranskat)abstract
- Latent heat thermal storage (LHTS) system is vital to reduce environment pollution. In the shell-and-tube heat accumulator, the position of the inner heating tube plays a vital role in the thermal storage. To analyze the effect of the inner tube position on the phase transition, a two-dimensional numerical model is developed. The structure has the minimum full melting time of 3480 s when the inner tube is 12 mm (L = 12 mm) from the center. Compared with L = 0 mm, the full melting time at L = 12 mm can be reduced by 13.4%.
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| 7. |
- Shahbazi, Sasha, et al.
(författare)
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Comparison of Four Environmental Assessment Tools in Swedish Manufacturing: A Case Study
- 2019
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- To achieve sustainable development goals, it is essential to include the industrial system. There are sufficient numbers of tools and methods for measuring, assessing and improving the quality, productivity and efficiency of production, but the number of tools and methods for environmental initiatives on the shop floor is rather low. Incorporating environmental considerations into production and performance management systems still generally involves a top-down approach aggregated for an entire manufacturing plant. Green lean studies have been attempting to fill this gap to some extent, but the lack of detailed methodologies and practical tools for environmental manufacturing improvement on the shop floor is still evident. This paper reports on the application of four environmental assessment tools commonly used among Swedish manufacturing companies—Green Performance Map (GPM), Environmental Value Stream Mapping (EVSM), Waste Flow Mapping (WFM), and Life Cycle Assessment (LCA)—to help practitioners and scholars to understand the different features of each tool, so in turn the right tool(s) can be selected according to particular questions and the industrial settings. Because there are some overlap and differences between the tools and a given tool may be more appropriate to a situation depending on the question posed, a combination of tools is suggested to embrace different types of data collection and analysis to include different environmental impacts for better prioritization and decision-making.
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| 8. |
- Shahbazi, Sasha, et al.
(författare)
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Material efficiency in manufacturing: swedish evidence on potential, barriers and strategies
- 2016
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 127, s. 438-450
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Tidskriftsartikel (refereegranskat)abstract
- Improved material efficiency is a key to improve the circular economy and capturing value in industry. Material efficiency reduces the generation of industrial waste, the extraction and consumption of resources, and energy demands and carbon emissions. However, material efficiency in the manufacturing sector, as a means of improving the recyclability, reusability, reduction and prevention of industrial waste, is little understood. This study aims to investigate, on a micro-level, further material efficiency improvement opportunities, barriers and strategies in selected manufacturing companies in Sweden, focusing on increasing waste segregation into high quality circulated raw material. Improvement opportunities at large global manufacturing companies are investigated; barriers hindering material efficiency improvement are identified and categorized at two levels; and strategies that have been deployed at manufacturing companies are reviewed. Empirical findings reveal (1) further potential for improving material efficiency through higher segregation of residual material from mixed and low quality fractions (on average, 26% of the content of combustible waste, in weight, was plastics; 8% and 6% were paper and cardboard, respectively); (2) the most influential barriers are within budgetary, information, management, employee, engineering, and communication clusters; (3) a lack of actual material efficiency strategy implementation in the manufacturing companies. According to our analysis, the majority of barriers are internal and originate within the manufacturing companies, therefore they can be managed (and eradicated if possible) with sufficient resources in terms of man hours, education and investment, better operational and environmental (waste) management, better internal communication and information sharing, and deployment of material efficiency strategies.
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| 9. |
- Farrokh, Mohammad, 1964-, et al.
(författare)
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DIASPORIC BAUXITE DIGESTION PROCESS SIMULATION
- 2010
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The alumina digestion process in the Bayer overall process like the other hydrometallurgical processes is under the effect of various factors and the control and optimization of quality and efficiency of the process and also reducing the energy consumption are of prime importance. Process simulation provides the possibility to investigate the impact of various factors and study the optimum conditions for obtaining the desired quality and reducing the energy consumption and environmental impact. In the digestion unit, the high pressure diasporic bauxite slurry, a mixture of ground bauxite, lime and caustic liquor, is decomposed. The bauxite slurry is preheated in the high pressure tube pre-heater and then is heated up to the decomposition temperature in the furnace. The dissolution takes place in the tubular digesters and resulting product, aluminate slurry, passes through the expanding stage, including 11 flash tanks to recover the thermal energy. In this paper the thermodynamic simulation consecutive stages of the digestion unit process including the property methods and the evaluation and verifying the simulation results against their accordance with the real conditions are studied. The obtained results showed that the outputs of the simulation have good and acceptable accordance with the empirical data. Using the simulation program; the results of some case studies showed that in the current situation, less than 70% of the energy generated in the dissolution process is directed to the pre-heaters. Also more than 30% of vapor generated in the dissolution process is dissipated and wasted. By using the vapor generated in the last two flash tanks, the efficiency of energy recycling will be increased and thus the water waste and environmental pollution will be decreased considerably.
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| 10. |
- Farrokh, Mohammad, 1964-
(författare)
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Thermodynamic process modeling and simulation of a diaspore bauxite digestion process
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bauxite ores which originated from separate mines have different characteristics, i.e. each bauxite ore has its own individual specifications. Jajarm bauxite is of the diaspore-chamosite type and its alumina to silica mass ratio is lower than other diaspore ores. Diaspore bauxite digestion in comparison with other bauxite types has more complicated operational conditions and requires higher temperature, pressure and caustic concentration. The present study was thus performed on the above mentioned digestion process and include two parts. First, the behavior of some key parameters of the process was experimentally investigated. Second, a simulation model was developed to predict the performance of the process, particularly thermal energy consumption. The model was validated with several sets of the industrial data and close agreement was found. The effects of various trends in pressure drops of the flash tanks on the slurry preheating were analyzed. The results showed that the proposed pressure profile can lead to an increase in the furnace inlet slurry temperature. Alternatively, it can lead to an appreciable decrease in the furnace fuel consumption, which is required for having the existing operating temperature. The generated vapor in different stages of the process was determined. A considerable amount of the generated water vapor and thermal energy were lost. The model was further developed to study the effect of using a part of these vapors on heat recovery. The simulation results showed that in the new design, the pre-heater sections can gain 5.71GJ/h additional heat and the fresh slurry temperature increases by 11°C. Therefore, the furnace required energy is reduced by 11.9%. The new design was implemented in the refinery and according to the energy department report, it has reduced the furnace fuel consumption by 8%, which is around 200kg of natural gas /h less than the earlier condition for every digestion line.
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