A near-infrared spectroscopic method and measurement system for moisture depth profiling is prese... more A near-infrared spectroscopic method and measurement system for moisture depth profiling is presented in this thesis. The measurement system is based on a fibre-optic light source and probes, and a hyperspectral imaging spectrograph. The probes feature six different measurement geometries, including a specular reflection measurement, and diffuse reflection and transmission measurements, all of which are measured in seven positions simultaneously. A theoretical analysis of the depth profiling capabilities of the system is presented, as well as laboratory tests of the system performance. Based on these, the analysis depth of the reflection moisture measurement in a 75 μm thick uncoated paper is estimated to be about 40 μm. It is also shown that the depth profiling properties depend on the average moisture content of the paper, and that the inclusion of a coating layer complicates the depth profiling. The use of the theoretical analysis results in the interpretation of the measurement ...
Mining and metal industries are essential for the wellbeing of people and societies in a modern w... more Mining and metal industries are essential for the wellbeing of people and societies in a modern world.All our appliances at home and day-to-day operations at work beneft from minerals, which have been excavated, enriched and processed into materials used to build the framework of our societies: tools, devices and infrastructure. Sustainable supply of raw materials is a major European challenge as EU countries contribute to more than 20% of the global consumption of metals and minerals, but only produce around 3% of the total supply. Mining has been ongoing for over thousand years in Europe and the long-standing activity has consumed many of the rich mineral deposits. As a result, we need more efcient mineral excavation and benefciation process control in order to remain competitive and to utilize our resources efciently and sustainably now and in the future. Tis sets requirements for better mineral characterisation tools in mineral drill core analysis, benefciation and mineral proce...
As a part of the H2020 SPIRE project, Intensified by Design (IbD®), mineral beneficiation process... more As a part of the H2020 SPIRE project, Intensified by Design (IbD®), mineral beneficiation process chain will be intensified in terms of more efficient usage of energy and raw materials. The work focuses on optimizing control of the grinding circuit, coarse flotation process, new solids measurements and soft-sensors, as well as adaptive dynamic mass balancing. All demonstrators are interconnected through plant-wide optimization. In this paper, the process intensification activities carried out at the mini-pilot scale mineral beneficiation plant are briefly described. The real-time adaptation strategy utilizing Differential Evolution for parameter estimation in a sliding window is presented. The initial results show a successful parameter estimation result even in a short time window.
Die Erfindung betrifft ein Verfahren zur Bestimmung des Feuchteprofils der Bahn in deren Dickenri... more Die Erfindung betrifft ein Verfahren zur Bestimmung des Feuchteprofils der Bahn in deren Dickenrichtung und weiter zur Verhinderung von Planlageabweichung in der mit Einsiebführung arbeitenden Trockenpartie einer Faserstoffbahnmaschine. Bei dem Verfahren wird an der wenigstens auf einer Seite gestützten Bahn (28) in einer MD-Messposition (30) an wenigstens einer Stelle in Bahnquerrichtung (CD) die Feuchte der Bahn in z-Richtung (43) unmittelbar gemessen, und auf der Grundlage dieser Messung wird das Trocknen der Bahn (28) geregelt. Die Erfindung betrifft auch eine entsprechende Anordnung.
Keksintö koskee menetelmää rainan tasopoikkeaman määrittämiseksi kuiturainakoneen kuivatusosalla.... more Keksintö koskee menetelmää rainan tasopoikkeaman määrittämiseksi kuiturainakoneen kuivatusosalla. Lisäksi menetelmässä mitataan suoraan rainan (28) kosteutta z-suunnassa (43) konesuuntaisessa (MD) mittauspositiossa (30) ainakin yhdessä poikkisuuntaisessa (CD) kohdassa, minkä perusteella rainalle (28) lasketaan tasopoikkeama. Keksintö koskee myös vastaavaa sovitelmaa. (Fig.3)
We have studied the ground state properties of two-dimensional 3 He -4 He mixtures at zero temper... more We have studied the ground state properties of two-dimensional 3 He -4 He mixtures at zero temperature. 3 He atoms with opposite spins form loosely bound dimers in free space and in low concentration mixtures with 4 He . The binding energy of the dimer ranges from milli-Kelvins near the saturation density to micro-Kelvins at the solidification density. The radius of such a weakly bound dimer is tens of Ångstöms. We also calculate the phase diagram of the mixture. The maximum solubility of 3 He ≈7% is determined by comparing chemical potentials in the pure and mixed fluids. The upper stability limit of the super-saturated mixture is obtained from the second derivative of the enthalpy. It becomes negative at the concentration 10-15% depending of the pressure, indicating a softening of the concentration-fluctuation mode. We also find an indication of the phase transition from the dimerized to atomic mixture.
We calculate microscopically the properties of the dilute 3 He component in a 3 He-4 He-mixture. ... more We calculate microscopically the properties of the dilute 3 He component in a 3 He-4 He-mixture. These depend on both, the dominant interaction between the impurity atom and the background, and the Fermi liquid contribution due to the interaction between the constituents of the 3 He component. We first calculate the dynamic structure function of a 3 He impurity atom moving in 4 He. From that we obtain the excitation spectrum and the momentum dependent effective mass. The pole strength of this excitation mode is strongly reduced from the free particle value in agreement with experiments; part of the strength is distributed over high frequency excitations. Above k ≥ 1.7Å −1 the motion of the impurity is damped due to the decay into a roton and a low energy impurity mode. Next we determine the Fermi-Liquid interaction between 3 He atoms and calculate the pressure-and concentration dependence of the effective mass, magnetic susceptibility, and the 3 He-3 He scattering phase shifts. The calculations are based on a dynamic theory that uses, as input, effective interactions provided by the Fermi hypernetted-chain theory. The relationship between both theories is discussed. Our theoretical effective masses agree well with recent measurements by Yorozu et al. (Phys. Rev. B 48, 9660 (1993)) as well as those by R. Simons and R. M. Mueller (Czekoslowak Journal of Physics Suppl. 46, 201 (1996)), but our analysis suggests a new extrapolation to the zero-concentration limit. With that effective mass we also find a good agreement with the measured Landau parameter F a 0 .
ABSTRACT We calculate the phase diagram of 3He-4He mixtures in two dimensions as a function of de... more ABSTRACT We calculate the phase diagram of 3He-4He mixtures in two dimensions as a function of density and 3He concentration. A number of features distinguish this system significantly from its three-dimensional counterpart. Specifically, we find that the 3He phase consists, at low 3He concentrations and positive pressures, of loosely bound dimers. The dimerized liquid phase separates at a 3He concentration of 2–3 % because the chemical potential of the 3He component in the mixture exceeds the chemical potential in the pure phase. Atomic 3He-4He mixtures can be found only in a metastable state in a concentration regime above 3%, where the mixture is stable against infinitesimal concentration fluctuations. The softening of concentration-fluctuation modes with decreasing 3He concentration is accompanied by a divergence of the 3He hydrodynamic effective mass, and the magnetic susceptibility vanishes. We verify, wherever possible, that our results are consistent with simulation data and exact estimates.
A near-infrared spectroscopic method and measurement system for moisture depth profiling is prese... more A near-infrared spectroscopic method and measurement system for moisture depth profiling is presented in this thesis. The measurement system is based on a fibre-optic light source and probes, and a hyperspectral imaging spectrograph. The probes feature six different measurement geometries, including a specular reflection measurement, and diffuse reflection and transmission measurements, all of which are measured in seven positions simultaneously. A theoretical analysis of the depth profiling capabilities of the system is presented, as well as laboratory tests of the system performance. Based on these, the analysis depth of the reflection moisture measurement in a 75 μm thick uncoated paper is estimated to be about 40 μm. It is also shown that the depth profiling properties depend on the average moisture content of the paper, and that the inclusion of a coating layer complicates the depth profiling. The use of the theoretical analysis results in the interpretation of the measurement ...
Mining and metal industries are essential for the wellbeing of people and societies in a modern w... more Mining and metal industries are essential for the wellbeing of people and societies in a modern world.All our appliances at home and day-to-day operations at work beneft from minerals, which have been excavated, enriched and processed into materials used to build the framework of our societies: tools, devices and infrastructure. Sustainable supply of raw materials is a major European challenge as EU countries contribute to more than 20% of the global consumption of metals and minerals, but only produce around 3% of the total supply. Mining has been ongoing for over thousand years in Europe and the long-standing activity has consumed many of the rich mineral deposits. As a result, we need more efcient mineral excavation and benefciation process control in order to remain competitive and to utilize our resources efciently and sustainably now and in the future. Tis sets requirements for better mineral characterisation tools in mineral drill core analysis, benefciation and mineral proce...
As a part of the H2020 SPIRE project, Intensified by Design (IbD®), mineral beneficiation process... more As a part of the H2020 SPIRE project, Intensified by Design (IbD®), mineral beneficiation process chain will be intensified in terms of more efficient usage of energy and raw materials. The work focuses on optimizing control of the grinding circuit, coarse flotation process, new solids measurements and soft-sensors, as well as adaptive dynamic mass balancing. All demonstrators are interconnected through plant-wide optimization. In this paper, the process intensification activities carried out at the mini-pilot scale mineral beneficiation plant are briefly described. The real-time adaptation strategy utilizing Differential Evolution for parameter estimation in a sliding window is presented. The initial results show a successful parameter estimation result even in a short time window.
Die Erfindung betrifft ein Verfahren zur Bestimmung des Feuchteprofils der Bahn in deren Dickenri... more Die Erfindung betrifft ein Verfahren zur Bestimmung des Feuchteprofils der Bahn in deren Dickenrichtung und weiter zur Verhinderung von Planlageabweichung in der mit Einsiebführung arbeitenden Trockenpartie einer Faserstoffbahnmaschine. Bei dem Verfahren wird an der wenigstens auf einer Seite gestützten Bahn (28) in einer MD-Messposition (30) an wenigstens einer Stelle in Bahnquerrichtung (CD) die Feuchte der Bahn in z-Richtung (43) unmittelbar gemessen, und auf der Grundlage dieser Messung wird das Trocknen der Bahn (28) geregelt. Die Erfindung betrifft auch eine entsprechende Anordnung.
Keksintö koskee menetelmää rainan tasopoikkeaman määrittämiseksi kuiturainakoneen kuivatusosalla.... more Keksintö koskee menetelmää rainan tasopoikkeaman määrittämiseksi kuiturainakoneen kuivatusosalla. Lisäksi menetelmässä mitataan suoraan rainan (28) kosteutta z-suunnassa (43) konesuuntaisessa (MD) mittauspositiossa (30) ainakin yhdessä poikkisuuntaisessa (CD) kohdassa, minkä perusteella rainalle (28) lasketaan tasopoikkeama. Keksintö koskee myös vastaavaa sovitelmaa. (Fig.3)
We have studied the ground state properties of two-dimensional 3 He -4 He mixtures at zero temper... more We have studied the ground state properties of two-dimensional 3 He -4 He mixtures at zero temperature. 3 He atoms with opposite spins form loosely bound dimers in free space and in low concentration mixtures with 4 He . The binding energy of the dimer ranges from milli-Kelvins near the saturation density to micro-Kelvins at the solidification density. The radius of such a weakly bound dimer is tens of Ångstöms. We also calculate the phase diagram of the mixture. The maximum solubility of 3 He ≈7% is determined by comparing chemical potentials in the pure and mixed fluids. The upper stability limit of the super-saturated mixture is obtained from the second derivative of the enthalpy. It becomes negative at the concentration 10-15% depending of the pressure, indicating a softening of the concentration-fluctuation mode. We also find an indication of the phase transition from the dimerized to atomic mixture.
We calculate microscopically the properties of the dilute 3 He component in a 3 He-4 He-mixture. ... more We calculate microscopically the properties of the dilute 3 He component in a 3 He-4 He-mixture. These depend on both, the dominant interaction between the impurity atom and the background, and the Fermi liquid contribution due to the interaction between the constituents of the 3 He component. We first calculate the dynamic structure function of a 3 He impurity atom moving in 4 He. From that we obtain the excitation spectrum and the momentum dependent effective mass. The pole strength of this excitation mode is strongly reduced from the free particle value in agreement with experiments; part of the strength is distributed over high frequency excitations. Above k ≥ 1.7Å −1 the motion of the impurity is damped due to the decay into a roton and a low energy impurity mode. Next we determine the Fermi-Liquid interaction between 3 He atoms and calculate the pressure-and concentration dependence of the effective mass, magnetic susceptibility, and the 3 He-3 He scattering phase shifts. The calculations are based on a dynamic theory that uses, as input, effective interactions provided by the Fermi hypernetted-chain theory. The relationship between both theories is discussed. Our theoretical effective masses agree well with recent measurements by Yorozu et al. (Phys. Rev. B 48, 9660 (1993)) as well as those by R. Simons and R. M. Mueller (Czekoslowak Journal of Physics Suppl. 46, 201 (1996)), but our analysis suggests a new extrapolation to the zero-concentration limit. With that effective mass we also find a good agreement with the measured Landau parameter F a 0 .
ABSTRACT We calculate the phase diagram of 3He-4He mixtures in two dimensions as a function of de... more ABSTRACT We calculate the phase diagram of 3He-4He mixtures in two dimensions as a function of density and 3He concentration. A number of features distinguish this system significantly from its three-dimensional counterpart. Specifically, we find that the 3He phase consists, at low 3He concentrations and positive pressures, of loosely bound dimers. The dimerized liquid phase separates at a 3He concentration of 2–3 % because the chemical potential of the 3He component in the mixture exceeds the chemical potential in the pure phase. Atomic 3He-4He mixtures can be found only in a metastable state in a concentration regime above 3%, where the mixture is stable against infinitesimal concentration fluctuations. The softening of concentration-fluctuation modes with decreasing 3He concentration is accompanied by a divergence of the 3He hydrodynamic effective mass, and the magnetic susceptibility vanishes. We verify, wherever possible, that our results are consistent with simulation data and exact estimates.
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Papers by Janne Paaso