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  • 1051.
    Zetterlund, Mikael Zetterlund
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Lastningseffektivitet Kristinebergsgruvan: Jämförelse mellan två lastningsmetoder2018Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
  • 1052.
    Zhang, Ping
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Botelho, Anneliese
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Dineva, Savka
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Woldemedhin, Biruk
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Field monitoring seismic response of underground excavations and rock bolts at kiirunavaara underground mine2019In: Rock Mechanics for Natural Resources and Infrastructure Development - Full Papers: Proceedings of the 14th International Congress on Rock Mechanics and Rock Engineering (ISRM 2019), September 13-18, 2019, Foz do Iguassu, Brazil / [ed] Sergio A.B. Fontoura; Ricardo Rocca; José Mendoza, Taylor & Francis, 2019, p. 1372-1379Conference paper (Refereed)
    Abstract [en]

    To assess the performance of underground excavations and ground support when subjected to mining-induced seismicity, a site has been instrumented at the Kiirunavaara mine. Geophones, multi-point extensometers and instrumented bolts were installed at the site. After the installation, several large seismic events (local magnitude>1.5) have occurred near the site and caused serious damages. The results from site monitoring indicate that the seismic waves are amplified near the excavation surface. The rock mass and rock bolts respond to mining-induced seismicity with step changes in displacement. The ejection velocity back-calculated from the energy absorbed in the rock bolts shows good agreement with the measured peak particle velocity (PPV). It is concluded that the scaling law used to evaluate the ground motion near excavation surface needs to be improved by considering velocity amplification. Repeated loading from multiple seismic events should be considered to assess rockburst damage.

  • 1053.
    Zhang, Ping
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, Ering
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    3DEC Numerical Analysis of the Interaction Between an Uneven Rock Surface and Shotcrete Lining2021In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453X, Vol. 54, no 5, p. 2267-2289Article in journal (Refereed)
    Abstract [en]

    Rock tunnels excavated using drilling and blasting technique in jointed rock masses often have a very uneven and rough excavation surface. Experience from previous studies shows that the unevenness of a rock surface has a large impact on the support effect of shotcrete lining. However, clear conclusions regarding the effect of 2D and 3D uneven surfaces were not obtained due to limited studies in the literature. The numerical analyses reported in this paper were made to investigate the influence of the surface unevenness of a circular tunnel opening on the support effect of shotcrete using a 3D numerical code (3DEC). The models were first calibrated with the help of observations and measured data obtained from physical model tests. The influential factors were investigated further in this numerical study after calibration had been achieved. The numerical analyses show that, in general, the unevenness of a tunnel surface produces negative support effects due to stress concentrations in recesses (compressive) and at apexes (tensile) after excavation. However, shotcrete sprayed on a doubly waved uneven surface has better support effect compared to shotcrete sprayed on a simply waved tunnel surface. The development of shear strength (specifically frictional strength) on the uneven interface between the shotcrete and the rock contributes to this effect, in the condition where bonding of the shotcrete does not work effectively. The interface is a crucial element when the interaction between the rock and shotcrete is to be simulated. When an entire tunnel surface is covered by shotcrete with high modulus, more failures will occur in the shotcrete especially when rock surface is uneven. Based on the numerical model cases examined, some recommendations on how to incorporate tunnel surface conditions (2D or 3D unevenness) in the design of a shotcrete lining are given.

  • 1054.
    Zhang, Ping
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Numerical investigation of dynamic response of a rockbolt under drop testing and simulated seismic loading conditions2019In: Ground Support 2019: Proceedings of the Ninth International Symposium on Ground Support in Mining and Underground Construction / [ed] Hadjigeorgiou, J.; Hudyma, M., Australian Centre for Geomechanics, 2019, p. 387-398Conference paper (Refereed)
    Abstract [en]

    When designing rockbolts for rockburst conditions, it is commonly assumed that the kinetic energy of an ejected rock block is absorbed by rockbolts. To obtain the energy absorption capacity of a rockbolt, drop testing has been widely used. The advantage of using a drop test to investigate the dynamic performance of rockbolts is that it can provide repeatable results. However, it is recognised that the drop test technique is a crude simulation of an actual seismic loading mechanism. To investigate the difference, numerical models were constructed to simulate the response of a rockbolt under both drop testing and simulated seismic loading conditions using the numerical code UDEC (Universal Distinct Element Code, Ver 6.0) (Itasca Consulting Group 2018). The seismic wave is simplified as a full cycle sinusoidal wave which generates the same ejection velocity magnitude on a reinforced rock block as the drop test. The rockbolt was found to fail under the simulated seismic loading condition but survived the drop test. This difference is because reflected seismic waves create additional displacement between the ejected rock block and adjacent rock block. The results indicate that impact energy or kinetic energy should be used carefully when determining the dynamic demand on rockbolts as it does not consider the critical interaction between seismic waves and the reinforced rock blocks. Additional parameter sensitivity studies showed how the frequency of a simulated seismic wave affects the dynamic response of rockbolts. The results can be used to improve our understanding on the dynamic response characteristics of ground support. The knowledge gained from the comparison can be used to improve the estimation of dynamic demand on rockbolts under rockburst conditions.

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  • 1055.
    Zhang, Steven E.
    et al.
    Natural Resources Canada, Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, Canada; Wits Mining Institute WMI, University of the Witwatersrand, Private Bag 3, 2050 Wits, South Africa.
    Nwaila, Glen T.
    Wits Mining Institute WMI, University of the Witwatersrand, Private Bag 3, 2050 Wits, South Africa.
    Bourdeau, Julie E.
    Natural Resources Canada, Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, Canada; Wits Mining Institute WMI, University of the Witwatersrand, Private Bag 3, 2050 Wits, South Africa.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering. School of Chemistry, University of Lincoln, Joseph Banks Laboratories, Green Lane, Lincoln, Lincolnshire, LN6 7DL, United Kingdom.
    Carranza, Emmanuel John M.
    Department of Geology, University of the Free State, 205 Nelson Mandela Dr, Bloemfontein, 9301, South Africa.
    Deriving big geochemical data from high-resolution remote sensing data via machine learning: Application to a tailing storage facility in the Witwatersrand goldfields2023In: Artificial Intelligence in Geosciences, E-ISSN 2666-5441, Vol. 4, p. 9-21Article in journal (Refereed)
    Abstract [en]

    Remote sensing data is a cheap form of surficial geoscientific data, and in terms of veracity, velocity and volume, can sometimes be considered big data. Its spatial and spectral resolution continues to improve over time, and some modern satellites, such as the Copernicus Programme's Sentinel-2 remote sensing satellites, offer a spatial resolution of 10 m across many of their spectral bands. The abundance and quality of remote sensing data combined with accumulated primary geochemical data has provided an unprecedented opportunity to inferentially invert remote sensing data into geochemical data. The ability to derive geochemical data from remote sensing data would provide a form of secondary big geochemical data, which can be used for numerous downstream activities, particularly where data timeliness, volume and velocity are important. Major benefactors of secondary geochemical data would be environmental monitoring and applications of artificial intelligence and machine learning in geochemistry, which currently entirely relies on manually derived data that is primarily guided by scientific reduction. Furthermore, it permits the usage of well-established data analysis techniques from geochemistry to remote sensing that allows useable insights to be extracted beyond those typically associated with strictly remote sensing data analysis. Currently, no generally applicable and systematic method to derive chemical elemental concentrations from large-scale remote sensing data have been documented in geosciences. In this paper, we demonstrate that fusing geostatistically-augmented geochemical and remote sensing data produces an abundance of data that enables a more generalized machine learning-based geochemical data generation. We use gold grade data from a South African tailing storage facility (TSF) and data from both the Landsat-8 and Sentinel remote sensing satellites. We show that various machine learning algorithms can be used given the abundance of training data. Consequently, we are able to produce a high resolution (10 m grid size) gold concentration map of the TSF, which demonstrates the potential of our method to be used to guide extraction planning, online resource exploration, environmental monitoring and resource estimation.

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  • 1056.
    Zhang, Zhiqiang
    et al.
    Xi’an University of Technology, Xi’an, China.
    Zhang, Ping
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Li, Yunxiang
    Xi’an University of Technology, Xi’an, China.
    Numerical Simulation of a Round Determinate Panel Test of Combined Concrete Panel and Welded Wire Mesh 2018In: Paper presented at the ISRM International Symposium - 10th Asian Rock Mechanics Symposium, Singapore, October 2018 / [ed] Z. Zhao; Y. Zhou; J. Shang, International Society for Rock Mechanics and Rock Engineering / Society for Rock Mechanics and Engineering Geology , 2018, article id ISRM-ARMS10-2018-146Conference paper (Refereed)
    Abstract [en]

    The sprayed concrete layer, together with external welded wire mesh, has been widely used as an important surface support in underground excavation in civil and mining engineering. Recently, the load carrying capability of combined concrete layer and welded wire mesh was evaluated by a round determinate panel (RDP) test. However, performance assessment by using RDP specimens is hindered by the testing boundary condition and the failure pattern and mechanism of combined concrete layer and welded wire mesh remains unclear. In this paper, the numerical model of the RDP test was set up by means of a FEM code, ABAQUS, and a series of numerical tests were carried out to investigate the failure mechanism and the influence of boundary condition on the performance of the RDP tests. To ensure the constitutive model of concrete embedded in ABAQUS and the material parameters were correctly used, the numerical models were first calibrated by the laboratory results with different concrete panel thickness without using welded wire mesh. After that, the performance of the combined concrete layer and welded wire mesh was examined by using the calibrated concrete model and mesh model and the failure mechanism of the combined specimens was obtained. The results show that the failure pattern matches the laboratory observation rather well and the peak load carrying capacity of the combined concrete layer and welded wire mesh panel is a little higher than that of the concrete only panel but the residual load carrying capacity has been improved. The boundary condition has large effect on the load-displacement curve, which is discussed in detail in the paper. The objective was to develop a numerical methodology which could be used to evaluate the load carrying capacity of combined concrete layer and welded wire mesh and thereby improve the assessment of the performance of shotcrete and welded wire mesh on site. 

  • 1057.
    Zhang, Zong-Xian
    et al.
    Oulu Mining School, University of Oulu, Oulu, FI-90014, Finland.
    Chi, Li Yuan
    State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, China.
    Yi, Changping
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    An empirical approach for predicting burden velocities in rock blasting2021In: Journal of Rock Mechanics and Geotechnical Engineering, ISSN 1674-7755, Vol. 13, no 4, p. 767-773Article in journal (Refereed)
    Abstract [en]

    An analytical relation between burden velocity and ratio of burden to blasthole diameter is developed in this paper. This relation is found to be consistent with the measured burden velocities of all 37 full-scale blasts found from published articles. These blasts include single-hole blasts, multi-hole blasts, and simultaneously-initiated blasts with various borehole diameters such as 64 mm, 76 mm, 92 mm, 115 mm, 142 mm and 310 mm. All boreholes were fully charged. The agreement between measured and calculated burden velocities demonstrates that this relation can be used to predict the burden velocity of a wide range of full-scale blast with fully-coupled explosive charge and help to determine a correct delay time between adjacent holes or rows in various full-scale blasts involved in tunnelling (or drifting), surface and underground mining production blasts and underground opening slot blasts. In addition, this theoretical relation is found to agree with the measured burden velocities of 9 laboratory small-scale blasts to a certain extent. To predict the burden velocity of a small-scale blast, a further study or modification to the relation is necessary by using more small-scale blasts in the future.

  • 1058.
    Zhong, Jin
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. Department of Electrical & Electronic Engineering, The University of Hong Kong, Hong Kong, China.
    Bollen, Math H. J.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    On the Way to Utilizing Green Hydrogen as an Energy Carrier—A Case of Northern Sweden2024In: Energies, E-ISSN 1996-1073, Vol. 17, no 7, article id 1514Article in journal (Refereed)
    Abstract [en]

    Low or even zero carbon dioxide emissions will be an essential requirement for energy supplies in the near future. Besides transport and electricity generation, industry is another large carbon emitter. Hydrogen produced by renewable energy provides a flexible way of utilizing that energy. Hydrogen, as an energy carrier, could be stored in a large capacity compared to electricity. In Sweden, hydrogen will be used to replace coal for steel production. This paper discusses how the need for electricity to produce hydrogen will affect the electricity supply and power flow in the Swedish power grid, and whether it will result in increased emissions in other regions. Data of the Swedish system will be used to study the feasibility of implementing the hydrogen system from the power system viewpoint, and discuss the electricity price and emission issues caused by the hydrogen production in different scenarios. This paper concludes that the Swedish power grid is feasible for accommodating the additional electricity capacity requirement of producing green hydrogen for the steel industry. The obtained results could be references for decision makers, investors, and power system operators.

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  • 1059.
    Zhong, Jin
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. Department of Electrical & Electronic Engineering, The University of Hong Kong, Hong Kong.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Rönnberg, Sarah
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Towards a 100% Renewable Energy Electricity Generation System in Sweden2021In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 171, p. 812-824Article in journal (Refereed)
    Abstract [en]

    Swedish government’s target is to have 100 per cent renewable electricity production by 2040. Currently, hydropower contributes the majority of renewable electricity generation of the country. The wind power capacity has increased significantly in the past decade. In this paper, practical data is used to study the possibility of reaching the 100% renewable electricity generation goal by replacing existing thermal generations with wind power generations. It is found that the Swedish electricity generation system can reach 100% renewable by tripling the existing wind power capacity combined with the existing hydropower in the country. Based on current growth rate of wind power installation, the goal could be reached within 20 years. Hourly simulation shows that 100 % renewable energy generation system composed by wind power and hydropower satisfy hourly operation requirements.

  • 1060.
    Zhou, Guanghong
    et al.
    Industrial Ecology, Department of Sustainable Development, Environmental Science and Engineering, School of Architecture and the Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Singh, Jagdeep
    Industrial Ecology, Department of Sustainable Development, Environmental Science and Engineering, School of Architecture and the Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Wu, Jiechen
    Industrial Ecology, Department of Sustainable Development, Environmental Science and Engineering, School of Architecture and the Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Sinha, Rajib
    Industrial Ecology, Department of Sustainable Development, Environmental Science and Engineering, School of Architecture and the Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Laurenti, Rafael
    Industrial Ecology, Department of Sustainable Development, Environmental Science and Engineering, School of Architecture and the Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Frostell, Björn
    Industrial Ecology, Department of Sustainable Development, Environmental Science and Engineering, School of Architecture and the Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Evaluating low-carbon city initiatives from the DPSIR framework perspective2015In: Habitat International, ISSN 0197-3975, E-ISSN 1873-5428, Vol. 50, p. 289-299Article in journal (Refereed)
    Abstract [en]

    Current low-carbon city initiatives were evaluated using the DPSIR (Drivingforces-Pressures-State-Impacts-Responses) causal-effect framework for investigating interactions between environmental issues and human activities. For effective management towards achieving a low-carbon city, integrating the pressure-based, driver-oriented DPSIR approach could help decision makers examine whether greenhouse gas (GHG) reduction approaches deal with the root causes of GHG emissions and work to-wards low-carbon city development goals. The DPSIR framework was used on 36 global cities to analyse the socio-economic dynamics of GHG emissions and their pressures on the environment, the state of the environment, related climate change impacts and responses from society. The results indicated that numerous cities have awareness of low-car bon plans and that most of these plans are pressure-based and driver-oriented. Most city plans recognise energy, transportation and building as the main driving forces for GHG emissions, which cause environmental pressures, and highlight technical responses to reduce GHG emissions pressures from these root causes. Inaddition, most plans recognise institutional and cognitional responses to low-carbon city development, such as: policies and legislation; departmental planning and cooperation; measuring, monitoring and reporting performance; capital invest-ment; community education and outreach; and stakeholder involvement.

  • 1061.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    A critical review of industrial management approaches for climate change mitigation2015Conference paper (Other academic)
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  • 1062.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Energiledning i energiintensiv industri: En syntes av ett forskningsprojekt2017Report (Other academic)
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  • 1063.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Exploring the influence of organisational chacteristics on benefits of environmental management systems2010In: Proceedings of 13th QMOD Conference on Quality and Service Sciences ICQSS / [ed] Ralf Woll; Michael Brusch, Cottbus: Brandenburg University of Technology , 2010Conference paper (Refereed)
    Abstract [en]

    Purpose - The purpose of this study is to explore the influence of organizational characteristics on the environmental benefits of environmental management system (EMS) adoption. Methodology/Approach - This study is a meta-study based on secondary analysis of data and findings published in more than 80 previous studies. As a meta-study it is a type of review but an attempt is made to identify patterns and relations not sought by the original authors.Findings - The results of this study indicate that the benefits of EMS seem to be independent of the drivers for adoption. Not only large organisations but also smaller ones benefit from EMS. EMS implementation in smaller organisations is associated with significant barriers, but improvement occurs because these organisations often look at environmental issues for the first time when adopting an EMS. EMS appears to be a functional tool not only in the industrial sector, but also in those more service-oriented organizations that have the most complex environmental impact. No significant differences in benefits from EMS have been found in different cultural settings. Research limitations/implications – Since the analysis is based on findings in previous studies, it is not possible to influence the data. The findings have to be validated with empirical studies preferable in the form of larger surveys. Originality/Value of paper – Adoption of EMS constitutes one of the most important elements of corporate social responsibility (CSR) and corporate sustainability in recent years. Most of the previous studies on the effects of environmental management systems (EMS) treat all organisations as one homogenous group and do not examine the benefits of EMS implementation in relation to the differences in organisational characteristics. However, it is plausible that the benefits do indeed depend on different organisational characteristics. During a review of EMS evaluation studies and other relevant literature, four characteristics have been identified that can be assumed to affect the outcome of EMS implementation; drivers for EMS adoption, organisation size, business sector and cultural setting. In addition to these organisational characteristics, other attributes most probably also affect the results of EMS adoption, but these characteristics where chosen since they, in contrast to other characteristics, could be identified in already published studies and therefore constitute a suitable point of departure for research penetrating deeper into the possible environmental benefits of EMS.

  • 1064.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    ISO 14001 Adoption and Environmental Performance: The Case of Manufacturing in Sweden2018In: ISO 9001, ISO 14001, and New Management Standards / [ed] Iñaki Heras-Saizarbitoria, Springer, 2018, p. 39-57Chapter in book (Refereed)
    Abstract [en]

    Environmental management systems based on the international standard ISO 14001 have become widespread in companies globally during the last two decades. This chapter aims to contribute knowledge as to which companies are most likely to adopt ISO 14001, environmental frontrunners or poor performers in need of effective approaches. In addition, the chapter aims to assess the impact of ISO 14001 on concrete environmental performance. The context in focus in this study is manufacturing companies in Sweden. The study focuses on changes in performance over a period of 12 years and includes both ISO 14001-certified companies and non-certified companies. The analysis has been carried out using statistical methods for five different environmental areas: air emissions, water emissions, resource use, energy use and waste. In none of these environmental areas have we been able to find any significant differences between certified and non-certified companies regarding performance improvement prior to ISO 14001-certification or the corresponding period in non-certified companies. Certain positive concrete effects as a result of the ISO 14001 adoption have been found but, in general, the standard seems to have limited effect on the improvement of corporate environmental performance. There are many examples in the literature that ISO 14001 has been successful under certain circumstances but at the same time it seems that ISO 14001-certification does not appear to be a guarantee of neither superior environmental performance nor concrete environmental improvements.

  • 1065.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    ISO 14001 adoption and industrial waste generation: the case of Swedish manufacturing firms2015In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 33, no 2, p. 107-113Article in journal (Refereed)
    Abstract [en]

    Adoption of environmental management systems (EMSs) based on ISO 14001 has constituted one of the most important developments in sustainable industry management in recent years. Previous research on the impact of EMSs has relied heavily on corporate representatives’ subjective perception of benefits. Moreover, studies tend to focus on the systems’ impact on firms’ overall environmental performance, not distinguishing between the differences in different environmental aspects. This study aims to contribute knowledge about the influence of certified EMSs on industrial waste generation based on objective industrial waste data derived from mandatory annual environmental reports. The study focuses on changes in waste generation over a period of 12 years and includes both ISO 14001-certified firms (66 firms) and non-certified firms (50 firms). Consideration is given to the improvement efforts in the firms before EMS adoption. Analysis has been carried out using statistical methods for three different industrial waste parameters: hazardous waste, waste to landfill and the total amounts of waste. The results indicate that the certified EMSs have no statistically significant effect on any of the three waste parameters.

  • 1066.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    ISO 14001 certification in manufacturing firms: a tool for those in need or an indication of greenness?2013In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 43, p. 37-44Article in journal (Refereed)
    Abstract [en]

    Adoption of environmental management systems constitutes one of the most important elements of corporate sustainability in recent years. The purpose of this study is to contribute knowledge as to which firms are most likely to adopt an environmental management system, those which are in greatest need of effective approaches or those which are already environmental frontrunners. A comparison between the improvement in environmental performance over a six-year period prior to ISO 14001 certification and the corresponding improvement in firms choosing not to adopt a system was performed. Environmental data was analyzed by using t-tests for six different areas: air emissions, water emissions, resource use, energy use, waste and overall environmental performance. In none of these environmental areas have we been able to find any statistically significant differences between certified and non-certified firms at 95% confidence level regarding the change in environmental performance prior to ISO 14001-certification or the corresponding period in non-certified firms. Our results indicate that it is equally likely that firms showing less or no improvement choose to implement and certify an environmental management system as it is for firms showing more improvement to do so.

  • 1067.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    ISO 14001 certification in Swedish firms: a tool for the needy or a symptom of greenness?2011In: Proceedings QMOD Conference on Quality and Service Sciences 2011: from learnability, innovability and sustainability : book of full papers / [ed] Carmen Jaca; Ricardo Mateo; Elizabeth Viles; Javier Santos, Pamplona: Servicios de Publicaciones Universidad de Navarra , 2011, p. 1949-1961Conference paper (Refereed)
  • 1068.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    The effects of environmental management system on Swedish manufacturing firms' environmental performance2010In: Proceedings of Corporate Responsibility Research Conference 2010 / [ed] Tobias Hahn, Marseille: Euromed Management School , 2010Conference paper (Refereed)
    Abstract [en]

    The corporate environmental management tool that has undoubtedly become the most popular in recent years is environmental management systems (EMS), which often are based on the international standard ISO 14001. With few exceptions, studies on effects of EMS are relying on firm representatives’ perceived benefits, which is problematic since firm representatives often have reason to give a positive image of their employer. This study therefore aims to contribute knowledge about the environmental effects of environmental management system based on more objective environmental data. The study focuses on changes in performance over a period of 12 years and includes both firms with an EMS (66 firms) and firms without systems (50 firms). Consideration is given to the improvement efforts in the firms before EMS adoption. Analysis has been carried out using statistical methods, e.g. t-test, for six different areas: air emissions, water emissions, resource use, energy use, waste and overall environmental performance. The analysis shows that there was no statistically significant difference concerning the change in the rate of improvement between certified and non-certified firms in any of the six areas.

  • 1069.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    The impact of ISO 14001 on corporate environmental performance: a study of Swedish manufacturing firms2016In: Journal of Environmental Planning and Management, ISSN 0964-0568, E-ISSN 1360-0559, Vol. 59, no 4, p. 587-606Article in journal (Refereed)
    Abstract [en]

    The debate concerning the environmental effectiveness of environmental management systems (EMS) based on ISO 14001 is still open and scholars have called for further studies that can explain the contrasting evidence in previous research. As a response, this study aims to contribute knowledge about the effects of ISO 14001-based EMS by presenting fact-based environmental data. The study focuses on changes in performance over a period of 12 years and includes both firms with an EMS (66 firms) and firms without one (50 firms). Consideration is given to the improvement efforts in the firms before EMS adoption making it possible to neutralize any selection effects where better environmental performance precedes ISO 14001 adoption. Analysis has been carried out using statistical methods for six different environmental areas. No statistically significant differences between certified and non-certified firms concerning the change in the rate of improvement could be found in any of the six areas. However, it can be suspected that EMS adoption has positive effects on energy use and waste production whereas the non-adopting firms seem to perform better concerning air emissions. These mixed results mirrors previous research, which is rather worrying considering the worldwide popularity of EMS based on ISO 14001 in industry.

  • 1070.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    The influence of ISO 14001 certification on industrial waste generation: the case of Swedish manufacturing firms2012Conference paper (Refereed)
    Abstract [en]

    Adoption of environmental management systems (EMS) and ISO 14001-certification of those systems constitutes one of the most important elements of sustainable industry management in recent years. Research on EMS is rather extensive, but with few exceptions, studies of the influence of EMS are relying heavily on firm representatives’ perceived benefits. Moreover, previous studies tend to focus on the systems impact on firms’ overall environmental performance, not identifying differences in different environmental aspects. This study aims to contribute knowledge about the influence of certified EMS on industrial waste generation based on objective industrial waste data derived from mandatory annual environmental reports. The study focuses on changes in waste generation over a period of 12 years and includes both ISO 14001-certified firms (66 firms) and non-certified firms (50 firms). Consideration is given to the improvement efforts in the firms before EMS adoption. Analysis has been carried out using statistical methods, for example t-test, for three different industrial waste parameters: hazardous waste, waste to landfill and the total amounts of waste. The results indicate that a certified EMS has a positive impact on hazardous waste reduction. No effect has been found regarding waste to landfill or the total amounts of waste.

  • 1071.
    Zobel, Thomas
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Malmgren, Charlotte
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    The impact of voluntary management systems on industrial energy efficiency2014In: Proceedings of the 20th Annual International Sustainable Development Research Conference / [ed] Martina Maria Keitsch, Trondheim: International Sustainable Development Research Society (ISDRS)/Norwegian University of Science and Technology (NTNU), Department of Product Design , 2014, p. 142-149, article id 3b18Conference paper (Refereed)
    Abstract [en]

    Voluntary industrial environmental management initiatives such as management systems based on the international standard ISO 14001has been widely spread over the world in recent years. Previous research on the influence of these systems relies heavily on how the benefits of the systems are perceived by companies’ representatives. Additionally, most studies tend to focus on the impact on the overall environmental performance of the companies, not identifying differences in different environmental aspects. The purpose of this paper is to explore the impact of voluntary environmental management systems on energy efficiency in Swedish manufacturing industry by means of objective industrial waste data derived from mandatory annual environmental reports. The study focuses on changes in energy efficiency over a period of 12 years and includes both ISO 14001-certified companies (66 companies) and non-certified firms (50 companies). Consideration is given to energy improvement efforts in the companies before ISO 14001 adoption. Analysis has been carried out using statistical methods for two different industrial energy parameters: electricity and fossil fuel consumption. The results indicate that ISO 14001 adoption has an impact on the energy efficiency regarding the use of fossil fuel. In contrast no impact has been found concerning the use of electricity.

  • 1072.
    Zobel, Thomas
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Matti, Simon
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Överlåtelse och återtagande av operativ miljötillsyn: Tillämpning av bestämmelser - Slutrapport2013Report (Other academic)
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  • 1073.
    Åberg, Annika
    et al.
    Luleå University of Technology.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Holger
    IIASA, International Institute for Applied Systems Analysis, Laxenburg, Austria.
    Evaluation and prediction of emissions from a road built with bottom ash from municipal solid waste incineration (MSWI)2006In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 355, no 1-3, p. 1-12Article in journal (Refereed)
    Abstract [en]

    In autumn 2001, a full-scale test road was built with municipal solid waste incineration (MSWI) bottom ash at the Dåvamyran landfill, Umeå, Northern Sweden. Leachates were collected from asphalted sections with either bottom ash or gravel as filling material. In this research, 12 months of ash leachate sampling were evaluated with respect to emissions of contaminants such as trace metals and chlorides (Cl). The usefulness of regression models describing trace metal mobility from bottom ash was also tested as predictive tools for reusability applications of MSWI bottom ash. Cl, Cu, and Cr had the highest mobility (considering leachate concentrations) in the ash leachate, though concentrations of Cl and Cu decreased during the sampling period (Cl from 10,000 to 600 mg l- 1; Cu from 1600 to 500 μg l- 1). An increased mobility of Cr during the autumns (about 3-4 times higher compared to the summer) was noted with a maximum value of nearly 70 μg l- 1 during autum 2001. Pb showed a very low mobility over the entire year with leachate concentrations of around 3-4 μg l- 1. Chemical equilibrium calculations using Minteq indicated that several Cu minerals were oversaturated in the leachate, thus mineral precipitation could be responsible for declining amounts of Cu in the leachate. Adsorption to iron oxides was found to be a probable explanation for the low mobility of Pb. A reasonably good agreement between regression models and field values were achieved for Ni, Pb, Zn, and Cu, while the models for Cd and Cr were less promising. Even though a large part of the variation (R2 = 61-97%) in the leaching experiment could be explained by only pH and L / S, field data were much more scattered than expected from field pH.

  • 1074.
    Åström, Krister
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Mineralogical characterization of gold in the Aurora ore zone in the Björkdal gold mine, northern Sweden – implications for metal recovery2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Aurora zone is an ore zone which was recently discovered in the Björkdal gold mine, northern Sweden, and it has been the main focus of mining and exploration activities for the past few years (Pressacco et al., 2020). The purpose of this project is to determine how gold occurs in the Aurora zone. A three-day long campaign was therefore done at the processing plant at the Björkdal mine where 11 000 tonnes of ore from the drive Aurora 370/1650 E+W were processed. The issue regarding the ore from the Aurora zone is that it has a lower recovery compared to the rest of the mine. 

    Six chip samples, 12 samples from the ingoing plant feed and two tailing samples were analyzed using optical microscopy, scanning electron microscopy (SEM), and automated mineralogy (QEMSCAN). This was done to determine the mineralogy, grain size distribution, mineral associations, textures and modal mineralogy which all are factors that could influence the metal recovery at the processing plant.

    The samples were prepared using the cold mounting method and epoxy mounts were created. After cutting, grinding, and polishing, the sections were ready to be examined. Optical microscopy was performed using a Nikon ECLIPSE E600 POL microscope. Ten epoxy mounts were carbon coated and automated mineralogy was performed on nine of them in a ZEISS Sigma 300 VP using a recipe (analysis mode) for “bright phase search”. Manual point-ID analysis was done using a ZEISS MERLIN SEM.

    Fifty gold grains were identified in this study, 48 of them in the chip samples and two of them in the ingoing-feed samples. 64% of them were associated with silicates, 22% were quartz associated, 12% were associated with bismuth minerals and 2% of them were associated with sulfides. The grain size distribution has a range between 0.7 and 19 μm and the median grain size is 4.8 μm. The gold grains identified from the Aurora zone have a significantly smaller median grain size than gold from other parts of the mine.

    The majority of the gold grains identified in this study, have a very fine grain size, are mainly associated with silicates and most prominently occur as inclusions. Gold that occurs in this way is typically difficult to recover in the processing plant and it seems like this is the main reason for the lower gold recovery from the Aurora ore zone. 

    No gold was found in the tailings, suggesting that the mineral process is performing well although no thorough conclusion can be made in regards of the processing. The lack of data for the different sample types in this project is an issue. Gold from the tailings must be identified and examined to draw any clear conclusions regarding the processing. For future work, it is therefore recommended to analyze more tailing samples and to implement hydroseparation at the sample preparation stage, to separate the heavier gold particles from lighter minerals. Then more gold will most likely get detected in the tailing samples.

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  • 1075.
    Ögren, Yngve
    et al.
    RISE AB, Box 726 SE-941 28, Piteå, Sweden.
    Sepman, Alexey
    RISE AB, Box 726 SE-941 28, Piteå, Sweden.
    Fooladgar, Ehsan
    RISE AB, Box 726 SE-941 28, Piteå, Sweden.
    Weiland, Fredrik
    RISE AB, Box 726 SE-941 28, Piteå, Sweden.
    Wiinikka, Henrik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. RISE AB, Box 726 SE-941 28, Piteå, Sweden.
    Development and evaluation of a vision driven sensor for estimating fuel feeding rates in combustion and gasification processes2024In: Energy and AI, ISSN 2666-5468, Vol. 15, article id 100316Article in journal (Refereed)
    Abstract [en]

    A machine vision driven sensor for estimating the instantaneous feeding rate of pelletized fuels was developed and tested experimentally in combustion and gasification processes. The feeding rate was determined from images of the pellets sliding on a transfer chute into the reactor. From the images the apparent area and velocity of the pellets were extracted. Area was determined by a segmentation model created using a machine learning framework and velocities by image registration of two subsequent images. The measured weight of the pelletized fuel passed through the feeding system was in good agreement with the weight estimated by the sensor. The observed variations in the fuel feeding correlated with the variations in the gaseous species concentrations measured in the reactor core and in the exhaust. Since the developed sensor measures the ingoing fuel feeding rate prior to the reactor, its signal could therefore help improve process control.

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  • 1076.
    Öhberg, Alexander
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Electrochemical oxidation of PFAS in soil conditions: Using Boron-doped diamond electrodes and iron electrodes2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Per- and polyfluoroalkyl substances (PFAS) are a rising topic in the field of contaminated sites around the world, with destruction of these being an area in dire need of innovation. Previous experiments of destructive character have been proven efficient using boron doped diamond electrodes (BDD) in small scale electrochemical cells. Further need for experimentation on actual site conditions is needed to further evaluate the use of this method, as well as research on alternative electrode materials to reduce the cost of remediation. 

    In this study, four cells containing contaminated soil were used: one with BDD electrodes, one with iron electrodes and two control cells. The iron electrodes were used to investigate if a less costly electrode material could achieve any degree of PFAS degradation. For the experiment a soil from a previous firefighting training site where firefighting foam containing high amounts of PFAS (620                     g/kg soil concentration) was used. During the first phase of the experiment a constant flow of deionized water was added to the cells containing the soil, and porewater was sampled at the in- and outflow along with the soil porewater, on a weekly basis, to evaluate the distribution of PFAS to provide information about possible degradation taking place. The extent of degradation was not quantified. However, due to differences in the molecular composition of the analysed PFAS a trend where short-chain PFAS increase throughout the experiment in the BDD cell indicated that short-chain PFAS were generated, which is an expected by-product in electrochemical oxidation of PFAS. No short-chain PFAS generation was seen in the iron electrode cell, nor was there a high amount present in the control cell leachate. 

    Further, leaching of PFAS was more efficient in the control cells, while PFAS in the BDD and iron electrode cell were retained or leaching was slowed down, most likely due to the electrode interaction with PFAS in porewater.Additionally a second phase where water flow through was halted and the cells were run in a batch mode was conducted to see PFAS degradation in stagnant conditions over time. In the stagnant cell in the second phase, only low PFAS concentrations in porewater were recorded while no degradation was established. 

    Further, fluoride analysis recorded F- concentrations in the range of    M, where the limit of detection was   M, which limited the confirmation of PFAS mineralisation in soil. 

    From this study insight of the difficulties with soil treatment of PFAS using electrokinetic method was highlighted, with sampling being a key factor in the accuracy of the result. For a more accurate establishment of the degradation experiments in a closed cell, with more extensive sampling throughout the entire column would be necessary. This is needed to generate a clearer picture of changes in PFAS concentration in the soil from the presumed degradation, coupled with a mass balance to provide the fate of PFAS in this type of setup. 

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  • 1077.
    Österlund, Heléne
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Lange, Katharina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Mikroplast i dagvatten och snö: Förekomst och avskiljning i biofilter, sedimentationsanläggningar och från snöhögar2022Report (Other academic)
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  • 1078.
    Lagerkvist, Anders (Editor)
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 20122012Report (Other academic)
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