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  • 43301.
    Zubeck, Hannele
    et al.
    University of Alaska, Anchorage.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Jensen, Pernille
    ARTEK, Technical University of Denmark.
    Nielsen, Mårten Holtegaard
    ARTEK, Technical University of Denmark.
    University of the Arctic's thematic network on Arctic engineering and science2009In: Cold Regions Engineering 2009: Cold Regions Impacts on Research, Design, and Construction / [ed] John Joseph Hinzmann; Howard D. Mooers, American Society of Civil Engineers (ASCE), 2009Conference paper (Refereed)
    Abstract [en]

    The Thematic Network in Arctic Engineering and Science (TN AES) was created In June 2008 when it was approved by the University of the Arctic's Council. The TN AES focuses on the development of sustainable technologies through engineering and science in the Arctic. The goals of the TN AES are twofold: The main goal is to improve the quality of life and allow the development of natural resources in the arctic through innovations in technologies used in the construction, maintenance and operation of infrastructure, housing, public/private facilities and equipment. The other goal is to assess the impact of climate change on these technologies. This paper introduces briefly the University of the Arctic to the engineering community and then describes current and planned network activities, such as joint education programs.

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    FULLTEXT01
  • 43302. Zuber, J.A.
    et al.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Origin of the Transscandinavian Igneous Belt: evidence from gravity measurements and geochemistry1993In: Abstratcts Volume: 19th Noftig Meeting, 1993Conference paper (Other academic)
  • 43303.
    Zuber, Josef A.
    Luleå tekniska universitet.
    Geological interpretation of gravity and aeromagnetic surveys over the Fellingsbro-Blixterboda granite1985In: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 107, no 3, p. 203-213Article in journal (Refereed)
    Abstract [en]

    Results of gravity and aeromagnetic measurements have been used for studying the subsurface shape of the Fellingsbro-Blixterboda granite massif, which was formed during the late stages of the Svecofennian orogeny, approximately 1800 Ma ago. The large negative gravity anomaly (ca. -120 gu) over the massif is interpreted to be caused by the relatively low density of the granite itself. The shape and size of the anomaly indicate that the exposed granite is thickest at its southern margin, reaching a depth of at least 15 km and possibly 20 km. To the north a considerable drop occurs in the gravity anomaly, suggesting a laccolithic form for the central and northern part of the granite massif. A main feature of the aeromagnetic anomalies over the Fellingsbro-Blixterboda granite is that they are conspicuously higher over the laccolithic part of the granite than over the intrusive, deep-going, stock-shaped granite, indicating a low magnetization of the latter part. Results of susceptibility determinations support this assumption. The origin and emplacement of the Fellingsbro-Blixterboda granite is apparently closely connected with the late orogeny of south central Sweden. The general shape of this granite massif is consistent with a mechanism of diapiric emplacement and a flow favoured by a zone of weakness in the Svecofennian basement

  • 43304.
    Zuber, Josef A.
    et al.
    Luleå University of Technology.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geophysical and geochemical evidence of Proterozoic collision in the western marginal zone of the Baltic Shield1990In: Geologische Rundschau, ISSN 0016-7835, E-ISSN 1432-1149, Vol. 79, no 1, p. 1-11Article in journal (Refereed)
    Abstract [en]

    New continental crust was formed in the Svecofennian domain of the Baltic Shield c. 1.9 Ga ago. Approximately 0.1-0.15 Ga later, new crust accreted to the SW part of the Shield. In this paper an attempt is made, on the basis of gravity measurements and lithogeochemistry, to describe the tectonic processes responsible for the continental growth c. 1.75-1.8 Ga ago. The Transscandinavian Granite Porphyry Belt (TGPB) separates the Svecofennian domain from the polymetamorphic terrain of the SW Swedish gneiss region. Red orthogneisses occurring immediately west of the TGPB are the deformed equivalents of the TGPB type granitoids, while grey orthogneisses, displaying a tonalitic-granodioritic trend and situated further west, were generated in a »volcanic arc« environment. The TGPB granitoids and the red SW Swedish gneisses represent a transition from this volcanic arc type rock to contemporaneous »within-plate« type granites intruded in the Svecofennian crust. The volcanic arc was forced against the Svecofennian crust in which large tensional fracture zones ensued with strike directions normal to the collision front. In such tensional environments the »withinplate« type granites were generated. In the collision zone the crust was down-warped, and huge amounts of granitic melts were generated at the base of the crust. This TGPB Magma rose upwards utilizing the fracture zone between the arc rocks, generated slightly earlier, and the Svecofennian crust. A relatively thin upper part of the TGPB that spread laterally westwards became strongly deformed during the collision (i.e. the red SW Swedish gneisses), while the major deep-reaching TGPB root zone that was not completely solidified yet, acted as a buffer against the foliation front.

  • 43305. Zuber, Josef A.
    et al.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Gravimetrical and geochemical studies of 1.8 Ga old granites in the Strängnäs-Enköping area, south central Sweden1991In: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 113, no 4, p. 309-318Article in journal (Refereed)
    Abstract [en]

    The Central Swedish Gravity Low is a distinct belt of gravity lows striking west-east from the Transscandinavian Igneous Belt to the Baltic Sea. Large homogeneous intrusions of c. 1.8 Ga old potassium rich granites with high contents of elements such as Y, HREE, and Nb, typical of granites generated in tensional environments, coincide with the gravity lows in the Fellingsbro-Lisjö area in the west and the Vallentuna area in the east. Between these areas only smaller and more heterogeneous granites of this age are exposed. The gravity measurements in the Strängnäs-Enköping area, however, clearly show the existence of large granite bodies beneath the present surface. The present and previous gravimetrical and lithogeochemical investigations suggest that c. 1.8 Ga ago, a tensional zone, now striking west-east, existed in the older crust. As a result of fusion of the lower crust in the tensional zone, a huge granitic ridge was formed along what is now the Central Swedish Gravity Low. The ridge was a heterogeneous mixture of granitic melts and solid residues. The Fellingsbro-type granites rose from this heterogeneous ridge through tensional fractures, and homogeneous intrusions were formed. The structural pattern of the tensional zone has a geometry remarkably similar to a modern oceanic ridge.

  • 43306.
    Zuo, Guangging
    et al.
    Luleå tekniska universitet.
    Ma, Jitang
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Some applications of neural networks for prediction of blast furnace irregularities1998In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 69, no 2, p. 41-48Article in journal (Refereed)
    Abstract [en]

    The on-line analysis of operational data and prediction of furnace irregularities, though difficult, are essential for the improvement of the control of blast furnace operation. Three models based on artificial neural networks for the recognition of top gas distribution, distributions of the heat fluxes through the furnace wall, and for the prediction of slips have been designed. The off-line test results showed that a trained perceptron network could recognize various types of top gas profiles. A classifier consisting of a self-organizing feature map network and a learning vector quantizer could classify the characteristic patterns of heat flux distribution; and a model based on a back propagation network could properly predict the probability of upcoming slips in advance. The most important operational variables needed for predicting slips have also been extracted. It has been proved that the neural network used has a good capability of predicting furnace irregularities

  • 43307.
    Zuo, Guangqing
    Luleå tekniska universitet.
    Improving the performance of the blast furnace ironmaking process2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In order to assist the operators' control activities and to further improve the performance of the blast furnace, efforts have been made to develop models for control of blast furnace operation and improvements of burden quality. The main objectives of the work were to design models for diagnosing and forecasting irregular furnace statuses and for predicting the silicon content of the hot metal, and to study the influence of the fluxes on the melting properties of fluxed pellets. A model for diagnosing the process status, consisting of six sub-models - recognition of the top gas profiles, classification of the heat flux distributions, prediction of the slips, comprehensive evaluation of the furnace process, diagnosis of channeling and cool furnace thermal state, has been designed. The off-line test results indicate that these models can detect and predict some upcoming and existing irregular process statuses, e.g. detecting the irregular top gas distribution, predicting slips three hours in advance and cool furnace thermal state two hours in advance. The most important operational parameters for predicting the upcoming slips are also extracted. A hybrid model for predicting the silicon content, consisting of a knowledge-based system and perceptron networks, has also been developed. The knowledge-based sub-system evaluates the process conditions and determines the applicability of a sub-model for forecasting. When the furnace operation is judged as normal, neural network models will make the predictions. When some irregular process statuses occur in the process, the knowledge-based system will perform the forecasting tasks. Test results show that the hybrid model for predicting the silicon content can make the forecasts about two hours in advance under various conditions, except the occurrence of serious irregular process statuses, e.g. more than 2 meters slip. The hit rate - a ratio of correct predictions - reached about 75% and 86% on acceptable prediction errors ±0.05% and 0.08% Si, respectively. Concerning the networks used for designing the model, test results have shown that a three-layer perceptron with two middle nodes trained with the algorithm - back-propagation with momentum, could give the 'best' prediction capability of the model. Algorithms - Quick Propagation and Resilient Propagation, can accelerate the training but cannot enhance the prediction ability of the model. Training using moving 'windowed data' can generate similar prediction results and enable online automatic update of the model. However, this approach demands greater computer resources. Radial basis Function network did not produce a better model. Softening and melting experimental studies show that the addition of basic fluxes, especially BOF-slag to self-fluxed pellets can considerably worsen the melting properties of pellets, even entirely block the separation of metallic iron from slag. The main reason is the high basicity and low FeO content of the slag, formed by the primary slag of pellets and fluxes in the course of melting. Therefore, it can be concluded that when using high-Fe self-fluxed pellets as the main iron-bearing burden, top-charging fluxes is not favorable to blast furnace operation.

  • 43308.
    Zuo, Guangqing
    Luleå tekniska universitet.
    Softening and melting characteristics of self-fluxed pellets with and without the addition of BOF-slag to the pellet bed2000In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 40, no 12, p. 1195-1202Article in journal (Refereed)
    Abstract [en]

    When using 100% self-fluxed pellets in the blast furnace burden, top charged fluxes, especially the BOF-slag, may cause irregularities in operation. The major reason has been theoretically attributed to the problematic slag formation in the furnace. As the melting of pellets is the first step of the slag formation process, the softening and melting properties of LKAB's self-fluxed pellets with and without addition of fluxes are studied experimentally. The results show that the softening and melting properties of the two types of LKAB's self-fluxed pellets are quite suitable for blast furnace operation. Contrarily, the melting-down characteristics of BOF-slag are variable and harmful to the slag formation under a reducing atmosphere. Adding 5% BOF-slag to the self-fluxed pellets can considerably worsen the softening and melting properties of pellets. It can either increase the softening and melting temperature interval substantially or cause the precipitation of solid phases, mainly di-calcium silicates, in the slag. It is quite likely that the resulting slag will therefore become very viscous, even entirely blocking the melting down of the pellets up to a temperature 1 520°C.

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    FULLTEXT01
  • 43309.
    Zuo, Guangqing
    Luleå tekniska universitet.
    Some applications of artificial neural networks in blast furnace operation1997Licentiate thesis, comprehensive summary (Other academic)
  • 43310.
    Zuo, Guangqing
    et al.
    Luleå tekniska universitet.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    An expert network for prediction and control of the silicon content of the hot metal1996In: The International Conference on Modelling and Simulation in Metallurgical Engineering and Materials Science: June 11 - 13, 1996, Beijing, China / [ed] Zongsen Yu, Beijing: Metallurgical Industry Press , 1996, p. 417-422Conference paper (Refereed)
    Abstract [en]

    To predict and control the silicon content of the hot metal ([%Si]) in blast furnace ironmaking process, an expert network consisted of a neural network model and an expert system has been established and tested off-line with the practical process data. The applicability of either the neural network model or the expert system for the prediction of [%Si] is determined by the experiential rules. In general, the predictions are made by the neural network model in the periods of the normal operation of the furnace, and performed by the expert system in the periods of the unsteady operation of the furnace. The operation guidance for adapting the furnace process is recommended by the expert system

  • 43311.
    Zuo, Guangqing
    et al.
    Luleå tekniska universitet.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Monitoring the blast furnace process using neural networks and knowledge-based system2001In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 72, no 4, p. 115-124Article in journal (Refereed)
    Abstract [en]

    To assist the daily control of blast furnace operation, models for diagnosing the irregular process status and for predicting the cool furnace thermal state have been developed. The diagnostic model consists of two sub-models. One is for evaluation of the various aspects of the process status based on fuzzy logic. The other is for the detection of the occurrence of channelling in the furnace based on neural networks. Tests using the actual process data have shown that the former sub-model can promptly detect the existing abnormal process status and give warnings of irregular process statuses, e.g. abnormal permeability of burden, high heat fluxes, etc. The latter sub-model can successfully extract the characteristic data patterns from a large amount of process data in connection with the occurrence of channelling and detect the existing channelling. For appropriately depicting the furnace thermal state, a thermal index and characteristic patterns of cool furnace thermal state have been derived using fuzzy logic and neural networks. Accordingly, two neural network models were designed for predicting the cool furnace thermal state. Either thermal index or characteristic patterns can be used to represent the cool furnace thermal state. Either model can be used to predict the upcoming cool furnace thermal state.

  • 43312.
    Zuo, Guangqing
    et al.
    Luleå tekniska universitet.
    Ma, Jitang
    Luleå tekniska universitet.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    A neural network model for predicting the silicon content of the hot metal at No. 2 blast furnace of SSAB Lulea1996In: 55th Ironmaking Conference proceedings: Meeting March 24-27, 1996 / [ed] D.H. Wakelin, Warrendale, Pa.: Iron and Steel Society , 1996, p. 211-221Conference paper (Refereed)
    Abstract [en]

    To predict the Si content of hot metal at No. 2 blast furnace, SSAB, Lulea Works, a three-layer back-propagation network model has been established. The network consists of twenty-eight inputs, six middle nodes and one output and uses a generalised delta rule for training. Different network structures and different training strategies have been tested. A well-functioning network with dynamic updating has been designed. The off-line test and the on-line application results showed that more than 80% of the predictions can match the actual silicon content in hot metal in a normal operation, if the allowable prediction error was set to plus/minus0.05% Si, while the actual fluctuation of the Si content was larger than plus/minus0.10% Si.

  • 43313.
    Zur, Lidia Z.
    et al.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi; CNR-IFN, Istituto di Fotonica e Nanotecnologie, CSMFO Lab. & FBK-CMM.
    Armellini, Cristina
    CNR-IFN, Istituto di Fotonica e Nanotecnologie, CSMFO Lab. & FBK-CMM.
    Belmokhtar, Saloua
    Laboratoire des Technologies Innovantes, LTI, Université Abdelmalek Essâadi, Tanger.
    Bouajaj, Adel
    Laboratoire des Technologies Innovantes, LTI, Université Abdelmalek Essâadi, Tanger.
    Cattaruzza, E.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia.
    Chiappini, A.
    CNR-IFN, Istituto di Fotonica e Nanotecnologie, CSMFO Lab. & FBK-CMM.
    Coccetti, F.
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”.
    Ferrari, M.
    CNR-IFN, Istituto di Fotonica e Nanotecnologie, CSMFO Lab. & FBK-CMM; Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi” .
    Gonella, Francesco
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”; Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia.
    Righini, Giancarlo C.
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”; CNR-IFAC, Istituto di Fisica Applicata Nello Carrara .
    Trave, Enrico
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Enrichi, Francesco
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”.
    Comparison between glass and glass-ceramic silica-hafnia matrices on the down-conversion efficiency of Tb3+/Yb3+ rare earth ions2019In: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 87, p. 102-106Article in journal (Refereed)
    Abstract [en]

    In this paper, the investigation of energy transfer efficiency in Tb3+-Yb3+ co-doped SiO2-HfO2 glass and glass-ceramic waveguides is presented. Cooperative energy transfer between these two ions allows to cut one UV or 488 nm photon in two 980 nm photons and could have important applications in improving the performance of photovoltaic solar cells. Thin films with different molar concentrations of rare earths, up to a total concentration of 21%, were prepared by a sol-gel route, using dip-coating deposition technique on SiO2 substrates. The ratio between Yb3+ and Tb3+ ions in all the prepared thin films is constant and equal to 4. The energy transfer between Tb3+ and Yb3+ ions in glass and glass-ceramic waveguides shows the higher efficiency for glass-ceramic with a maximum quantum transfer efficiency of about 190% for the sample containing 19% of rare earths.

  • 43314.
    Zurita, G.
    Luleå tekniska universitet.
    Analysis of measurements of the engine combustion noise using wavelets transform1996In: Proceedings of Nordic Acoustical Meeting, NAM 96 / [ed] Klaus Riederer; Tapio Lahti, Espoo: Helsinki University of Technology , 1996, p. 181-185Conference paper (Refereed)
  • 43315.
    Zurita, G.
    et al.
    Luleå tekniska universitet.
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Sundbäck, U.
    Luleå tekniska universitet.
    Measurement aspects of structural vibration and diesel combustion noise1994In: Proceedings of Nordic Acoustical Meeting, NAM 94 / [ed] Henrik S. Olesen, Aarhus: Danish technological institute , 1994Conference paper (Refereed)
  • 43316.
    Zurita, Grover
    Luleå tekniska universitet.
    Vibration based diagnostics of diesel engines2000In: Structural dynamics: recent advances ; proceedings of the 7th international conference : University of Southampton, from 24th to 27th July 2000 / [ed] N. S. Ferguson, Southampton: Institute of Sound and Vibration Research , 2000Conference paper (Refereed)
  • 43317.
    Zurita, Grover
    et al.
    Luleå tekniska universitet.
    Haupt, Dan
    Vibration based diagnostics of the combustion process in ethanol fueled-engine2000In: COMADEM 2000: proceedings of 13th International Congress on Condition Monitoring and Diagnostic Engineering Management : December 3-8, 2000, Houston, Texas, USA, Haymarket, Va: Society for Machinery Failure Prevention Technology , 2000, p. 607-616Conference paper (Refereed)
    Abstract [en]

    Due to stringent regulations, tremendous efforts have been made worldwide in monitoring and diagnosing combustion engines. However, there is still a large need to further develop optimization models that facilitate the understanding of the relationship between engine parameters and parameters such as noise and exhaust emissions. The aim of present study was to investigate the potential use of vibration based diagnostics for prediction of different parameters such as noise, exhaust emissions, Pmax and the dp/d alpha . The method is based on a reconstruction of the cylinder pressure from vibration measurements on the engine surface. A three factorial central composite face design was used for the tests involving different running conditions (i.e. speeds and loads) and different blends of rap seed oil methyl esther (RME)/ethanol. Principal component analysis (PCA) and partial least squares (PLS) were thereafter used for establishing models that show the relationship between speed, load, amount of RME and responses such as cylinder pressure, exhaust emissions and sound pressure. The results show that the reconstructed cylinder pressure can be used for diagnostics and control by allowing an accurate estimation of Pmax and dp/d alpha . Furthermore, the method used is also applicable for determining apparent net heat release rate and hence the exact time of the start of the combustion process. A comparison between measured and predicted values of NOx, noise, Pmax and dp/d alpha showed a good predictive power of the established models.

  • 43318.
    Zurita, Villarroel Grover
    Luleå tekniska universitet.
    Multivariate analysis and wavelet transform analysis of diesel engine combustion noise1996Licentiate thesis, comprehensive summary (Other academic)
  • 43319.
    Zurita-Villarroel, G.
    et al.
    Luleå tekniska universitet.
    Haupt, Dan
    A new approach to diagnostics of the combustion process in diesel engines using vibration measurements. Part 2: Reconstruction of cylinder pressure from vibration measurements2003In: International Journal for Transformative Research, ISSN 1027-5851, E-ISSN 2360-7866, Vol. 8, no 2, p. 68-76Article in journal (Refereed)
    Abstract [en]

    There is a steadily growing demand for reliable, non-invasive measurement methods which can be used to monitor combustion in diesel engines. An effective, non-invasive method would make it possible for those using diesel engines to economically detect malfunctions during combustion. The main objective of this paper is to show how, through reconstruction, it is possible to generate data on combustion parameters, which can then be used for engine diagnostics. The combustion parameters are the maximum cylinder pressure (pmax, ) and the derivative of the pressure rise (dp/da). The idea is based on reconstruction by using the transfer function, TF, from the combustion chamber to the engine surface and the measured vibration response signal of the engine surface. The analysis is based on a non-linear method called complex cepstrum and signal processing techniques. The TFs were modified to fit slightly different situations such as other cylinders of the same engine; where use can be made of symmetry. A new approach based on a new tailor-made window for reconstruction of the cylinder pressure is also presented. A matrix with engine TFs for varying speed and load was obtained. The matrix can be used as a data bank of TFs for reconstruction of the cylinder pressure at different operating conditions. An extensive analysis of the cycle-to-cycle variations was carried out, both for the measured and reconstructed cylinder pressure. The main parameters of the cylinder pressure; the maximum cylinder pressure (pmax, ) and the derivative of the pressure rise (dp/da), are thoroughly examined in order to validate the procedure.

  • 43320.
    Zurita-Villarroel, G.
    et al.
    Luleå tekniska universitet.
    Haupt, Dan
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Reconstruction of cylinder pressure through multivariate data analysis: for prediction of noise and exhaust emissions2004In: Noise Control Engineering Journal, ISSN 0736-2501, E-ISSN 2168-8710, Vol. 52, no 4, p. 154-163Article in journal (Refereed)
    Abstract [en]

    A new approach for reconstructing diesel engine cylinder pressure is presented. The technique is based on vibration measurements on the engine surface with subsequent reconstruction of the cylinder pressure by direct use of multivariate data analysis (MVDA). In order to investigate and evaluate the usefulness of the proposed technique, data from earlier experiments with four in-line, six cylinder, heavy-duty diesel engines have been used. One of the engines, running on ethanol, was tested according to a three factorial central composite face at different speeds and loads, as well as different blends of ethanol/ignition improver. The other engines, running on ordinary diesel, were tested with various loads and speeds. All of the measurements, i.e. cylinder pressure, sound pressure levels, vibration, and exhaust emissions, were performed simultaneously. The results demonstrated that MVDA models could accurately reconstruct cylinder pressures for all six cylinders in a diesel/ethanol engine. The differences between predicted and observed maximum cylinder pressure for 800 rpm were just 0-5%. The investigations also showed the potential of the method to estimate noise emissions and emission of NO x from the ethanol engine; a single partial least square (PLS) model could be used to predict noise and exhaust emissions at three different loads

  • 43321.
    Zurita-Villarroel, Grover
    et al.
    Luleå tekniska universitet.
    Pettersson, Esbjörn
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Multivariate analysis of engine noise and exhaust emissions from an ethanol-fueled diesel engine1997In: Proceedings of the 1997 noise and vibration conference / [ed] Bernard J. Challen, Warrendale, Pa.: Society of Automotive Engineers, Incorporated , 1997Conference paper (Refereed)
    Abstract [en]

    The engine manufacturers have to meet more and more stringent regulations on both noise and exhaust emissions in the future requiring extensive optimization of all parameters of the engine. Soft modeling with statistically designed experiment (SDE) and Multivariate Analysis (MVA) can be an aid in this work. The analyses are based on cylinder pressure data, engine data and exhaust emissions data, with all measurements performed simultaneously. The effects of changes in fuel quality, load, speed, and injection timing on combustion noise and exhaust emissions were investigated using SDE and MVA. The engine was a modified 6-cylinder, direct-injection diesel engine running on ethanol. The paper demonstrates the applicability of experimental design and multivariate methods for modeling and minimization of noise and exhaust emissions.

  • 43322.
    Zurita-Villarroel, Grover
    et al.
    Luleå tekniska universitet.
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    A new approach to diagnostics of the combustion process in diesel engines using vibration measurements. Part 1: Reconstruction of cylinder pressure from vibration measurements2003In: International Journal for Transformative Research, ISSN 1027-5851, E-ISSN 2360-7866, Vol. 8, no 2Article in journal (Refereed)
    Abstract [en]

    There is a steadily growing demand for reliable, non-invasive measurement methods which can be used to monitor combustion in diesel engines. An effective, non-invasive method would make it possible for those using diesel engines to economically detect malfunctions during combustion. The main objective of this paper is to show how, through reconstruction, it is possible to generate data on combustion parameters, which can then be used for engine diagnostics. The combustion parameters are the maximum cylinder pressure (pmax, ) and the derivative of the pressure rise (dp/da). The idea is based on reconstruction by using the transfer function, TF, from the combustion chamber to the engine surface and the measured vibration response signal of the engine surface. The analysis is based on a non-linear method called complex cepstrum and signal processing techniques. The TFs were modified to fit slightly different situations such as other cylinders of the same engine; where use can be made of symmetry. A new approach based on a new tailor-made window for reconstruction of the cylinder pressure is also presented. A matrix with engine TFs for varying speed and load was obtained. The matrix can be used as a data bank of TFs for reconstruction of the cylinder pressure at different operating conditions. An extensive analysis of the cycle-to-cycle variations was carried out, both for the measured and reconstructed cylinder pressure. The main parameters of the cylinder pressure; the maximum cylinder pressure (pmax, ) and the derivative of the pressure rise (dp/da), are thoroughly examined in order to validate the procedure.

  • 43323.
    Zurita-Villarroel, Grover
    et al.
    Luleå tekniska universitet.
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Wavelet transform analysis of measurements of engine combustion noise1997In: Proceedings of the 1997 noise and vibration conference / [ed] Barnard J. Challen, Warrendale, Pa.: Society of Automotive Engineers, Incorporated , 1997Conference paper (Refereed)
    Abstract [en]

    Wavelet transform analysis is capable of revealing aspects of data that other techniques miss; such aspects are trends, and discontinuities in higher derivates. This method can often compress or de-noise a signal without any appreciable degradation and it provides accurate information on the localization of energy content in time and frequency. The wavelet transform method has been applied to the analysis of combustion noise and piston slap in order to identify the effects on the engine structure vibration. The experimental results showed that combustion noise and piston slap were successfully detected from the acceleration signals picked up by external transducers in the outer wall of an in-line, 6-cylinder diesel engine.

  • 43324.
    Zurita-Villarroel, Grover
    et al.
    Luleå tekniska universitet.
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Pettersson, Esbjörn
    Reconstruction of the cylinder pressure from vibration measurements for prediction of exhaust and noise emissions in ethanol engines1999In: Proceedings of the 1999 Noise and Vibration Conference: [Noise and Vibration Conference and Exposition, Traverse City, Michigan, May 17 - 20, 1999], Warrendale, Pa: Society of Automotive Engineers, Incorporated , 1999Conference paper (Refereed)
    Abstract [en]

    There are growing demands for condition monitoring of IC engines, and therefore any method in order to improve the performance of the engines ought to be evaluated. This paper proposes a new approach for the prediction and optimisation of noise and exhaust emissions in IC engines. The idea is to reconstruct the cylinder pressure from vibration measurements on the engine surface by using the complex cepstrum method. The reconstructed cylinder pressure is further used as input in multivariate models, based on cylinder pressure, for estimating noise and exhaust emissions. This paper demonstrates the applicability of the method for modelling of noise and exhaust emissions.

  • 43325. Zwahlen, Carmen
    et al.
    Wogelius, Roy
    University of Manchester.
    Hollis, Cathy
    University of Manchester.
    Holland, Greg
    University of Manchester.
    Reaction path modelling illustrating the fluid history of a natural CO2-H2S reservoir2019In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 109, article id 104391Article in journal (Refereed)
    Abstract [en]

    Despite the increasing interest in geologic co-sequestration of CO2 and H2S, the long-term consequences of the chemical interactions involved in this process remain largely unknown on a reservoir scale. A Mississippian aged CO2-H2S reservoir in LaBarge Field, Wyoming, USA is an ideal study site to investigate mineral and fluid reactions related to gaseous H2S and CO2. We conducted two reaction path models based on mineralogical, fluid, gas, and stable isotope compositional data to discern the role of CO2 influx upon the generation of H2S through thermochemical sulphate reduction (TSR). We discriminate between two models-one in which TSR is triggered by temperature at a given burial depth and one where TSR is triggered by ingress of CO2. The reaction path model based upon burial-controlled TSR and later CO2 influx is consistent with mineralogical observations and stable isotope measurements from drill cores. The models show that CO2 influx leads to calcite precipitation which is only limited by the calcium concentration in the fluid. This modelling approach is useful in constraining the timing of fluid flux in the reservoir and gives further insight into the mineralogical consequences of the gas, water, and rock interactions occurring in the reservoir. In terms of geologic co-sequestration this implies that the addition of CO2 into a reducing carbonate system can result in calcite precipitation, instead of anhydrite as previously thought. Furthermore, it is only limited by the availability of Ca2+ and will therefore not diminish the amount of H2S in the system.

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  • 43326.
    Zwisele, Bertram
    et al.
    Argus GmbH.
    Rosenkranz, Jan
    Nordwig, André
    Fraunhofer Institut FIRST.
    Simulation mechanischer Aufbereitungsprozesse in der Abfallbehandlung2007In: Mechanisch-biologische Abfallbehandlung und automatische Abfallsortierung: Internationale Tagung MBA 2007 ; Tagungsband (Originalsprachenausgabe) ; 22. - 24. Mai 2007 / [ed] Matthias Kuehle-Weidemeier, Göttingen: Cuvillier Verlag, 2007, p. 364-376Conference paper (Refereed)
  • 43327.
    Zámečníková, Martina
    et al.
    Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic.
    Gustafsson, Magnus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nyman, Gunnar
    Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
    Soldán, Pavel
    Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic.
    Formation of CO+ by radiative association II2020In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 492, no 3, p. 3794-3802Article in journal (Refereed)
    Abstract [en]

    Radiative association of an oxygen atom with a carbon cation is investigated using quantal and semiclassical methods. The total rate coefficient for spontaneous radiative association of O(2s22p4, 3P) with C+(2s22p, 2P) on the doublet manifold is determined from the corresponding cross-sections. The cross-sections for the 12 Σ - → A2 II, 22 Σ - → A2II, and C2 Δ → A2II continuum-bound processes are calculated either semiclassically, in combination with the Breit-Wigner approach, or fully quantum mechanically. In the temperature range 10-10 000 K, our recommended total rate coefficient, obtained from these calculations and the data of Zámecniková et al. (2019), slowly increases from 7.5 × 10-18 cm3s-1 to 2.1 × 10-17 cm3s-1. Corresponding aspects of the CO+ and CO formations in SN 1987A are discussed

  • 43328.
    Zámečníková, Martina
    et al.
    Charles University.
    Soldán, Pavel
    Charles University.
    Gustafsson, Magnus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nyman, Gunnar
    University of Gothenburg.
    Formation of CO+ by radiative association2019In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 489, no 2, p. 2954-2960Article in journal (Refereed)
    Abstract [en]

    We theoretically estimate formation rate coefficients for CO+ through the radiative association of C+(2P) with O(3P). In 1989, Petuchowski et al. claimed radiative association to be the most important route for CO+ formation in SN 1987A. In 1990, Dalgarno, Du and You challenged this claim. Therefore, in this study, we improve previous estimates of the radiative association rate coefficients for forming CO+ from C+(2P) and O(3P). To do this, we perform quantum mechanically based perturbation theory calculations as well as semiclassical calculations, which are combined with Breit–Wigner theory in order to add the effect of shape resonances. We explicitly include four electronic transitions. The required potential energy and transition dipole-moment curves are obtained through large basis set multireference configuration interaction electronic structure calculations. We report cross-sections and from these we obtain rate coefficients in the range of 10 –10 000 K, finding that the CO+ formation rate coefficient is larger than the previous estimate by Dalgarno et al. Still our results support their claim that in SN 1987A, CO is mainly formed through radiative association and not through the charge transfer reaction CO+ + O → CO + Oas earlier suggested by Petuchowski et al.

  • 43329.
    Zühlke, Per
    et al.
    Winternet.
    Lysholm, Jack
    Winternet.
    Stene, Fredrik
    Sundbybergs Rehab och Fysioterapi.
    Tegner, Yelverton
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Postural stability after concussion in ice hockey players2008In: Svensk idrottsmedicinsk förenings vårmöte: Stockholm 2008, Svensk idrottsmedicinsk förening , 2008Conference paper (Other academic)
  • 43330. Ärlemalm, Tore
    Recognition failure and cue-dependence1997In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 38, no 3, p. 183-187Article in journal (Refereed)
  • 43331. Ärlemalm, Tore
    Recognition failure of recallable words: a cue-dependent view1996Doctoral thesis, comprehensive summary (Other academic)
  • 43332. Ärlemalm, Tore
    Recognition failure: the influence of semantic cue-target integration - a short note1996In: European Journal of Cognitive Psychology, ISSN 0954-1446, E-ISSN 1464-0635, Vol. 8, no 2, p. 205-214Article in journal (Refereed)
    Abstract [en]

    The observed probability of recognition given recall regularly adheres to what is predicted by the Tulving-Wiseman function. However, three types of exceptions have been observed: Cue overlap and poor cue-target integration cause an enhanced dependence, whereas good cue-target integration causes a diminished dependence between cued recall and recognition. In the present experiment, a diminished dependence between cued recall and recognition was demonstrated for good semantic cue-target integration. Conversely, poor semantic cue-target integration leads to an enhanced dependence between the two tests (see Gardiner & Tulving, 1980). The data were interpreted using the notion of cue-dependence (A rlemalm & Nilsson, 1994) and the semantic assimilation hypothesis (Ronnberg et al., 1991), which is a special case of cue-dependence.

  • 43333. Ärlemalm, Tore
    et al.
    Nilsson, Lars-Göran
    Umeå University, Department of Psychology.
    Recognition failure and integration1994In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 35, no 3, p. 271-280Article in journal (Refereed)
    Abstract [en]

    Explored recognition failure of recallable words (poor integration), using confidence ratings given to recall responses. 70 Ss (aged 15-35 yrs) were instructed to learn word pairs in such a way that they would be able to recall the target word when the cue word was presented. Ss were given either instruction about shallow coding (the words had the same letters) or deep coding instruction (words were meaningfully related). Ss then performed confidence ratings of responses of both the recognition and cued recall test. Results indicate that very poor integration produces a deviation above the function, whereas a very good integration produces a deviation below the function. The effect of integration (and cue overlap) is explained by means of a conceptualization cue dependency. Support is also given to the notion that an enhanced variability of goodness of encoding contributes to an enhanced dependence between recall and recognition

  • 43334. Ärlemalm, Tore
    et al.
    Nilsson, Lars-Göran
    Umeå University, Department of Psychology.
    Recognition failure of recallable words: exception due to poor integration1992In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 33, no 3, p. 266-276Article in journal (Refereed)
    Abstract [en]

    The phenomenon of recognition failure of recallable words shows a remarkable regularity across a wide variety of experimental conditions. A quadratric function, referred to as the Tulving-Wiseman (E. Tulving and S. Wiseman; see record 1978-07206-001) function, summarizes this regularity. A few cases of deviation from this have been identified and classified into 2 categories of exceptions to this function. An experiment with 40 Ss (aged 15-42 yrs) was designed to deal with 1 of these categories, namely the exception that occurs because of poor integration between cue and target information of studied word pairs. An index based on confidence ratings of recall responses was developed to assess variability in integration. Poor integration was demonstrated especially for 1 presentation of low associative word pairs, and significant deviations from the function was obtained for this condition

  • 43335.
    Åberg, Alf
    Luleå tekniska universitet.
    Mutagena effekter av thiokarbanater1985Licentiate thesis, monograph (Other academic)
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  • 43336.
    Åberg, Anna Christina
    et al.
    Akademiska sjukhuset, Uppsala.
    Lundin-Olsson, Lillemor
    Umeå universitet, Institutionen för Samhällsmedicin och Rehabilitering.
    Rosendahl, Erik
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Förebygg fall och fallskador i samband med vård: nationell satsning för ökad patientsäkerhet2008Report (Other academic)
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  • 43337.
    Åberg, Anna Christina
    et al.
    Department of Public Health and Caring Sciences/Geriatrics, Uppsala University.
    Lundin-Olsson, Lillemor
    Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University.
    Rosendahl, Erik
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Implementation of evidence-based prevention of falls in rehabilitation units: A staff's interactive approach2009In: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 41, no 13, p. 1034-1040Article in journal (Refereed)
    Abstract [en]

    Objective: To provide strategies to assist healthcare professionals in the area of rehabilitation to improve prevention of falls. Design: A conceptual framework is described as a foundation for the proposal of 2 intertwined strategies, of intervention and implementation, which target the questions: Which strategies for intervention represent the current best evidence? and: How can these strategies be implemented and continuously developed? Results: Strategies for multifactorial and multiprofessional fall preventive interventions are presented in terms of a "fall prevention pyramid model", including general, individualized, and acute interventions. A systematic global fall risk rating by the staff is recommended as an initial procedure. Fall event recording and follow-up are stressed as important components of local learning and safety improvement. Development of implementation strategies in 3 phases, focusing on interaction, facilitation and organizational culture, is described Conclusion: A well-developed patient safety culture focusing on prevention of falls will, when successfully achieved, be seen by staff, patients and their significant others as being characteristic of the organization, and will be evident in attitudes, routines and actions. Moreover, it provides potential for positive side-effects concerning organizational and clinical improvements in additional areas

  • 43338.
    Åberg, Anna Cristina
    et al.
    School of Education, Health and Social Studies, Dalarna University.
    Halvorsen, Kjartan
    Department of Information Technologies, Division of Systems and Control, Uppsala University.
    From, Ingrid
    School of Education, Health and Social Studies, Dalarna University.
    Bergman Bruhn, Åsa
    School of Education, Health and Social Studies, Dalarna University.
    Oestreicher, Lars
    Department of Information Technology, Division of Visual Information and Interaction, Uppsala University.
    Melander Wikman, Anita
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    A Study Protocol for Applying User Participation and Co-Learning: Lessons Learned from the eBalance-Project2017In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 14, no 5, article id E512Article in journal (Refereed)
    Abstract [en]

    The eBalance project is based on the idea that serious exergames-i.e., computer gaming systems with an interface that requires physical exertion to play-that are well adapted to users, can become a substantial part of a solution to recognized problems of insufficient engagement in fall-prevention exercise and the high levels of fall-related injuries among older people. This project is carried out as a collaboration between eight older people who have an interest in balance training and met the inclusion criteria of independence in personal activities of daily living, access to and basic knowledge of a computer, four staff working with the rehabilitation of older adults, and an interdisciplinary group of six research coordinators covering the areas of geriatric care and rehabilitation, as well as information technology and computer science. This paper describes the study protocol of the project's initial phase which aims to develop a working partnership with potential users of fall-prevention exergames, including its conceptual underpinnings. The qualitative methodology was inspired by an ethnographical approach implying combining methods that allowed the design to evolve through the study based on the participants' reflections. A participatory and appreciative action and reflection (PAAR) approach, accompanied by inquiries inspired by the Normalization Process Theory (NPT) was used in interactive workshops, including exergame testing, and between workshop activities. Data were collected through audio recordings, photos, and different types of written documentation. The findings provide a description of the methodology thus developed and applied. They display a methodology that can be useful for the design and development of care service and innovations for older persons where user participation is in focus.

  • 43339.
    Åberg, Anne-Maj
    et al.
    Åbo universitet.
    Lahtinen, Sinikka
    Åbo universitet.
    Toropainen, Outi
    Luleå University of Technology, Department of Arts, Communication and Education.
    Används explicita grammatikregler under skrivprocessen?2019Conference paper (Refereed)
  • 43340.
    Åberg, Anne-Maj
    et al.
    Åbo universitet.
    Mäkilä, Mari
    Åbo universitet.
    Vaakanainen, Veijo
    Åbo universitet.
    Toropainen, Outi
    Luleå University of Technology, Department of Arts, Communication and Education.
    Lahtinen, Sinikka
    Åbo universitet.
    Om användning av explicita grammatikregler under en skrivprocess.2018Conference paper (Refereed)
  • 43341.
    Åberg, Annika
    et al.
    Luleå tekniska universitet.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Holger
    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.

  • 43342.
    Åberg, Hans
    Luleå tekniska universitet.
    General relativistic quantum mechanics: intrinsic spin theory1993Report (Other academic)
    Abstract [en]

    On a Lorentz-manifold, a mathematically intrinsic spin-theory (meaning that the spin-operators and spin-fields themselves are tensors) is constructed (for arbitrary spin), the reason being that this is what you need in order to compute the generalization of the Einstein equation in general relativity, for particles with spin. Some of the corresponding (total) metric variations are also described, and from those, one can see that it gives rise to stress-energy tensors with positive statistical energy-densities, the latter being necessary in order to create a quantum field theory. This spin-theory only exists, in its completeness, in a four-dimensional Lorentz metric space, since it depends on the fact that the square of the Hodge star operator is minus one when acting on two-forms.

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  • 43343. Åberg, J. A.
    et al.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemical alteration associated with Au-bearing quartz veins at the Björkdal gold deposit, Skellefte district, northern Sweden1999In: Gold '99 Trondheim: bPrecambrian gold in the Fennoscandian and Ukrainian shields and related areas : abstract volume / [ed] Nigel J. Cook; Krister Sundblad, Trondheim: American Speech-Language-Hearing Association, 1999, p. 173-175Conference paper (Other academic)
  • 43344. Åberg, J. A.
    et al.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Petrographic- and chemical characteristics of alteration associated with Au-bearing quartz veins at the Bjorkdal gold deposit, Skellefte District, northern Sweden1999In: Mineral deposits; processes to processing: proceedings of the Fifth biennial SGA meeting and the Tenth quadrennial IAGOD symposium / [ed] C.J. Stanley, Rotterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1999, p. 1005-1008Conference paper (Refereed)
  • 43345. Åberg, Sture
    Smörjning av hjul och räls med fordonsinstallerat smörjsystem2005Report (Other academic)
    Abstract [sv]

    Nötningen av räl och hjul uppstår i kontakytan mellan räl och hjul. Den är störst i kurvor i kontaktytan mellan räl och hjul. De faktorer som påverkar nötningen är bland annat kurvradie, trafikbelastning i Mbton, STAX, fordonshastigheter, rälsmaterial, fordonstyp, rälsstatus, hjulstatus, antalet axelpassager och friktionen mellan räls - hjul. Normalt nöts rälsens yttersträng i kurvor och motsvarande hjulringar ned kraftigast. För att minska slitage på hjul och räls tillsätts smörjmedel. Man skiljer på två olika principer när det gäller smörjning: Flange wear (smörjmedel appliceras på lokens hjulflänsar) Friction management (smörjmedel appliceras på rälshuvudet Top of Rail) Genom att applicera smörjmedel på rälshuvudena i kurvor minskar slitaget på rälsmaterialet. Detta görs i Sverige med fasta Clicomaticutrustningar som är i drift under vår - höst i norra Sverige och hela Sverige i södra delarna av landet. Ingen smörjning sker vintertid. SJ och Green Cargo har lokinstallerade system för smörjning direkt på rälshuvudet i syfte att minska slitaget på efterföljande vagnshjul. Syftet med denna förstudie är att: Översiktligt beskriva befintliga fordonsmonterade system för smörjning av räls och hjulflänsar Kartlägga behovet i Sverige avseende smörjning från lok. Kortfattat beskriva vilka leverantörers smörjsystem som kan uppnå kraven som finns i Sverige avseende kurvradier, vinterförhållanden och STAX. Prisbilder på loksmörjningssystem Styrning av rälssmörjapparater. Förstudien visar att det är tekniskt, underhållsmässigt och ekonomiskt motiverat att använda smörjapparater som är monterade på lok för att minska sidoslitaget i kurvor och samtidigt ge minskat hjulslitage på lok och vagnar. Som ett led i målsättningen att effektivisera smörjningen av hjul och räls bör en fordonsmonterad smörjutrustning provas. Ett på marknaden etablerat system bör testas med dokumenterad erfarenhet från kallt klimat och tunga transporter typ norra USA eller Kanada. Smörjmedlet bör antingen appliceras som Top of Rail alltså på rälshuvudet eller direkt på lokets flänsar. Smörjutrustning bör installeras dels på det första drivande loket dels på det sista multipelkopplade lokets bakre del för smörjning av efterföljande vagnshjul enligt bild 3. Systemet ska kunna avläsa när kurva uppträder samt kurvans radie, lämpligast via inbyggda sensorer. Olika smörjmedel bör testas för att klara kraven avseende risken för glidning, miljökrav, friktion mellan hjul och räls i kurvor och funktion i kallt klimat samt appliceras utan problem med igenstoppning av munstycken. Följande två leverantörer bör studeras närmare före val av testutrustning: Friction Management Services system TrackGlide - Top of Rail Willy Vogel AG system för hjulflänssmörjning. Eftersom det finns flera intressanta leverantörer för hjulflänssmörjning kan inbjudan gå till ytterligare någon eller några. Utifrån en närmare analys där såväl applikation på lok, kostnad för utrustning, styrning, service, förutsättningarna för körning vintertid, dokumenterade smörjeffekter mm väljs en leverantör ut. Installation av testutrustning bör göras på ett av MTAB:s IORE-lok

  • 43346. Åberg, Sture
    et al.
    Sundgren, Anders
    Förstudie ReRail2005Report (Other academic)
    Abstract [sv]

    Visionen är att Rerail skall bli en framtida ny produkt inom järnvägssektorn som förlänger livslängden, effektiviserar underhållet och ger en lägre livstidskostnad. Design och tillverkning av Rerail ska göras i Norrbotten och levereras till olika kunder runt om i världen. Målet med detta arbete är att: Beskriva och verifiera kraven för att få göra skarpa test i Banverkets spåranläggningar Definiera produkterna och koppling till kundbehov och kundnyttan Definiera krav som underlag för godkännande av Banverket för test Beskriva marknadspotentialen för produkterna Utföra vissa grundläggande tester i laboratoriemiljö Kostnadsanalys för kommande steg enligt projektplanen Analysera konkurrenter och möjliga samarbetspartners Skissa på finansieringsmodeller för det fortsatta arbetet Skapa förutsättningarna för skarpa test hos potentiella kunder Förväntade sluteffekter är att utifrån genomförda mål kunna starta nästa etapp i arbetet med ReRail.

  • 43347.
    Åborg, Carl
    et al.
    Luleå tekniska universitet.
    Fernström, Elisabeth
    Statshälsan Research.
    Ericson, Mats O.
    Kungliga tekniska högskolan, KTH.
    Work content and satisfaction before and after a reorganisation of data entry work1998In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 29, no 6, p. 473-480Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to analyse the psychosocial and physical effects of a reorganisation of data entry work at a data processing unit with 153 employees. The reorganisation was planned to redistribute the repetitive work and improve health and satisfaction as well as efficiency. Methods used were questionnaires and, for a sub-group of 22 participants, interviews, diaries and video recordings. During the one-and-a-half-year study period the data processing unit was closed down and the employees transferred to units with more varied tasks. The reorganisation gave opportunities to improve working conditions. The results of this study show that important improvements were achieved. The majority of the 22 participants got less data entry work and the changes permitted a better work-load distribution. However, the work content after the reorganisation still did not provide satisfactory mental variation for most of the subjects, and the changes did not seem to affect health complaints.

  • 43348.
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Acoustic highlights in Nordic light weight building tradition - focus on ongoing development in Swedish: Distinguished lecture at BNAM 2010 in Bergen, Norway2010In: BNAM 2010, Bergen Norway, 2010Conference paper (Other academic)
    Abstract [en]

    The paper shows a selection of common light weight structures that are predominant today in the Nordic countries. Construction drawings are shown as well as measurement results from labs and in situ. Special focus is addressed towards modern Swedish constructions which will be included in the new Swedish national research programme for sound insulation in light weight houses. The ways to construct that are most predominant today can be categorised in mainly five types: timber in combination with boards, steel beams in combination with boards, thin board beams in combination with boards, more massive plywood board beams in combination with relatively massive plywood boards, integrated massive timber T-beams integrated with massive cross laminated plates. Production concepts vary from a delivery of flat elements to delivery of almost key-ready apartment volumes. The acoustic key question is not to produce breaking sound insulation at any cost, but to deliver cost-efficient solutions that can be designed for the sound insulation class that is ordered and paid for. Some solutions how this is dealt with are presented where examples for flanking transmission, suspended ceiling problems and floor stiffness solutions are shown.

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  • 43349.
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Aspects on how to design less noisy diesel engines1996In: Proceedings of Nordic Acoustical Meeting, NAM 96 / [ed] Klaus Riederer; Tapio Lahti, Espoo: Helsinki University of Technology , 1996, p. 113-120Conference paper (Refereed)
  • 43350.
    Ågren, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Design av tysta dieselmotorer1997In: SVIB Vibrationsforskningsdag, 1997Conference paper (Refereed)
864865866867868869870 43301 - 43350 of 44830
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