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Tiivistelmä. Teknologia on olennainen osa nyky-yhteiskuntaa ja yhteiskunta kehittyy koko ajan yhä teknologisempaan suuntaan. Teknologian kehityksen takia tulevaisuudessa tullaan tarvitsemaan uusia innovaatioita, jotta voidaan säilyttää kestävä kehitys ja ratkaista kestävyysvaje. Tämän takia tulevaisuudessa tullaan tarvitsemaan enemmän teknologian, tekniikan, matemaattisten sekä luonnontieteellisten alojen osaajia. Teknologiakasvatus ja STEAM-toiminta pyrkivät vastaamaan tulevaisuuden osaajatarpeeseen innostamalla lapsia jo pienestä pitäen teknologian, tekniikan, matematiikan ja luonnontieteiden pariin. Teknologiakasvatuksella ja STEAM-toiminnalla oppilaille pyritään samalla opettamaan tulevaisuuden taitoja, kuten ongelmanratkaisun, luovan- ja kriittisen ajattelun, sekä ryhmätyöskentelytaitoja. Tutkielman tavoitteena on perehtyä teknologiakasvatukseen sekä STEAM-toimintaan ja tarkastella näiden kahden eroja ja yhtäläisyyksiä niiden määritelmien, tavoitteiden ja opetusmenetelmien kautta. Tutkimuksen teoreettinen viitekehys koostuu teknologiakasvatuksen, STEM:in ja STEAM:in määritelmistä sekä näiden yhtäläisyyksistä ja eroista määritelmien ja tavoitteiden tasolla. Tutkimuksessani pääpaino sijoittuu teknologiakasvatukseen ja STEAM:iin, mutta käsittelen myös STEM:iä sekä sen määritelmää, sillä se on olennainen osa STEAM:ia ja sen kehitystä. Olen toteuttanut tutkimukseni kirjallisuuskatsauksena ja tarkastelen aihettani aikaisempien tutkimusten perusteella. Teknologiakasvatus ja STEAM ovat ajankohtaisia aiheita, sillä teknologiakasvatus on ollut osa suomalaista perusopetusta jo useamman vuoden ajan, kun taas STEAM on suomalaisessa koulumaailmassa vielä suhteellisen tuore lähestymistapa opetukseen. Koska teknologiakasvatus on kentällä jo tuttu, olisi hyvä tarkastella ja tutkia STEAM:ia tarkemmin, jotta tietoisuutta ja ymmärrystä STEAM:ista saataisiin vietyä myös kentälle. Tutkimuksessa selviää, että teknologiakasvatuksella ja STEAM-toiminnalla on useita yhtymäkohtia keskenään. Molemmilla on myös yhteyksiä konstruktivistiseen oppimiskäsitykseen ja konstruktivistisiin opetusmenetelmiin.

Funding Information: The authors of PTB are grateful to Ingmar Müller who designed, set up and characterized the PQEDs calibrated by PTB and to Uwe Johannsen who set up and improved the cryogenic radiometer calibration facility of PTB. The research leading to these results has received funding from the European Community’s Seventh Framework Programme, ERA-NET Plus, under Grant Agreement No. 217257, from the European Metrology Research Programme (EMRP) Project SIB57 ‘New Primary Standards and Traceability for Radiometry’ and from the project 18SIB10 chipS.CALe (EMPIR). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. The EMPIR programme is co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme. EI acknowledges the support by the Academy of Finland Flagship Programme, Photonics Research and Innovation (PREIN), decision number: 320167. Publisher Copyright: © 2022 BIPM & IOP Publishing Ltd. The stability of induced junction silicon photodiodes used to construct the predictable quantum efficient detector (PQED) has been studied over a time period of a decade by measurements of its spectral responsivity against absolute cryogenic radiometers (CR) in two independent laboratories at CMI and PTB. PQEDs operated at room temperature show a long-term temporal stability within 150 ppm over a broad spectral range during a 10-year period, well within the range of the claimed measurement uncertainty values of the CRs. This long term stability fulfills one of the fundamental requirements to establish a new primary standard for the measurement of power of optical radiation.

This paper develops an operation strategy for hybrid power production units (turbine integrated with energy storage) participating in the balancing of the power grid. The developed strategy targets the reduction of the mechanical stress of the hybrid’s turbine unit by utilizing the available storage capacity. The problem is addressed using the methods of operations research combined with the receding horizon control approach. The benefits of the operational strategy are demonstrated via numerical simulations.

This paper presents a robust soft sensor for estimating heat exchanger fouling in combustion–thermal power plant context. The approach is data–driven and focuses on identifying the effect of plant load changes to fouling estimation. Proposed method is applied to real process measurements and results are presented. The method consists of two blocks; a static energy balance calculation block for “traditional” fouling indicator calculation and a dynamic subspace identification block for finding sootblowing– and load level dynamics components of the static fouling indicator signal. Results from applying the proposed method to real plant data show that load level dynamics can be decoupled from static fouling estimate.

This paper presents the development and mathematical analysis of an open-channel flow model. A tanks-in-series model relying on systems engineering perspectives is constructed. Through a series of assumptions, the obtained nonlinear model is approximated by a linear dynamics, and its asymptotic modal behavior is analysed in infinite dimensions using rigorous mathematical machinery. The analysis exploits the repeating tridiagonal structure of the system matrix using Chebyshev polynomials and elaborates the dependence of the modal dynamics on the so-called flow coefficient, which accounts for the description of the flow of the model. The analysis presented in this paper reveals that using constant flow coefficient for flow description in cascade arrangement of liquid storages results in physically meaningless asymptotic modal behavior. The asymptotic modal behavior is well defined if the flow coefficient is an affine function or higher-order polynomial of the number of elements in the cascade structure.

Lataa OA-artikkeli, kun julkaistu. Light-emitting diodes (LEDs) have many applications in optical metrology. Depending on the measurement scheme, an LED might be driven, for example, using constant current, amplitude or pulsewidth modulated current, or current pulses. We present the design and characterization of a transconductance amplifier (TCA) optimized to drive LEDs in optical metrology applications. The device is capable of delivering peak and root mean square (rms) currents up to 10 and 1 A, respectively, and has a selectable transconductance ranging from 100 mu text{S} to 10 S. The typical cutoff frequency for the current output is around 10 MHz for various types of LEDs.

Foils made of different materials are often used as reflective insulators. Many manufacturers aim to accurately measure their optical properties to estimate and improve their performance. However, flat reflectance reference samples used in measurements do not correctly represent reflective insulators and cause discrepancies between different measurement techniques. The current work presents a method for modelling surface shape of appropriate reflectance reference samples that could be produced by additive manufacturing. The method is based on studying the reflection distribution of reflective insulators and is described with an example of aluminium foil. The method's performance is validated using Monte-Carlo simulations.

Cholesterol accumulation in late endosomes is a prevailing phenotype of Niemann-Pick type C1 (NPC1) mutant cells. Likewise, annexin A6 (AnxA6) overexpression induces a phenotype reminiscent of NPC1 mutant cells. Here, we demonstrate that this cellular cholesterol imbalance is due to AnxA6 promoting Rab7 inactivation via TBC1D15, a Rab7-GAP. In NPC1 mutant cells, AnxA6 depletion and eventual Rab7 activation was associated with peripheral distribution and increased mobility of late endosomes. This was accompanied by an enhanced lipid accumulation in lipid droplets in an acyl-CoA:cholesterol acyltransferase (ACAT)-dependent manner. Moreover, in AnxA6-deficient NPC1 mutant cells, Rab7-mediated rescue of late endosome-cholesterol export required the StAR-related lipid transfer domain-3 (StARD3) protein. Electron microscopy revealed a significant increase of membrane contact sites (MCS) between late endosomes and ER in NPC1 mutant cells lacking AnxA6, suggesting late endosome-cholesterol transfer to the ER via Rab7 and StARD3-dependent MCS formation. This study identifies AnxA6 as a novel gatekeeper that controls cellular distribution of late endosome-cholesterol via regulation of a Rab7-GAP and MCS formation. © 2019, The Author(s).

10 pags., 8 figs., 4 tabs. -- Open Access funded by Creative Commons Atribution Licence 3.0, In this paper, the fisheye camera method is validated for spatial non-uniformity corrections in luminous flux measurements with integrating spheres. The method was tested in eight integrating spheres with six LED lamps, and the determined angular intensity distributions and spatial non-uniformity correction factors were compared with the results of five goniophotometers. The average closeness score, describing the similarity between any two distributions, was 94.6 out of 100 for the distributions obtained using the fisheye camera method when compared with the goniophotometric results. The average closeness score for the five goniophotometers, when each goniophotometer was compared with the other four, was 96.6. On average, the relative deviation between the two methods was 0.05% when calculating the spatial corrections. The most significant sources of uncertainty for the fisheye camera method were large, view-obstructing sphere elements residing close to the camera port., The work leading to this study is partly funded by the European Metrology Programme for Innovation and Research (EMPIR) Project 15SIB07 PhotoLED ‘Future Photometry Based on Solid State Lighting Products’. The EMPIR initiative is cofunded by the European Union’s Horizon 2020 research and innovation programme and the EMPIR Participating States. Acknowledges the funded position of Aalto ELEC doctoral school and the support of the Tutkijat Maailmalle program.

Submitted document is an extended abstract.

Dipyrromethene difluoride-cholesterol (TopFluor-Cholesterol, TF-Chol) is a widely used cholesterol analogue due to its excellent fluorescence properties and considerable similarity with natural cholesterol in terms of membrane partitioning. However, the suitability of TF-Chol for detecting lysosomal cholesterol deposition has recently been questioned. Here, we highlight the fact that the method of lipid delivery and the analysis of time-point both affect the membrane distribution and labeling pattern of TF-Chol, similarly as with radiolabeled cholesterol. Lysosomal sterol accumulation characteristic to a lysosomal storage disease is most readily detected when the probe is introduced via the physiological route, i.e. as a sterol fatty acid ester in low-density lipoprotein particles. When administered to cells from solvent, lysosomal sterol sequestration becomes evident after an overnight equilibration between membranes. Non

CIE 2019, Washington DC, June 14 to 22, 2019. -- http://washington2019.cie.co.at, Angular intensity distributions of light sources are traditionally measured using goniophotometers. Usually, goniophotometers are expensive to obtain and resource intensive to operate, due to requirements of a dedicated laboratory and the time consuming nature of the measurements. In addition to other applications, such as lighting design, angular intensity distribution data are used for spatial corrections to increase accuracy of luminous flux measurements with integrating spheres. Because goniometric measurements are so laborious, many laboratories omit the spatial correction altogether, increasing their measurement uncertainty by up to a few percent, depending on the integrating sphere and the light source under test. Previously, the fisheye camera method was developed to enable faster and more cost-effective measurements of angular intensity distributions of light sources. Using the fisheye camera method, such angular distribution is obtained in a matter of seconds from a fisheye camera image captured through a port of an integrating sphere, while the sphere is illuminated by the lamp under test. The method was reported in CIE 2017 Midterm Meeting in Jeju, where doubts were presented about the wide applicability of the method and its comparability with traditional goniophotometers. In this study, the performance of the method is confirmed. The fisheye camera method is validated by measuring six LED lamps in eight integrating spheres of various configurations, and by comparing the obtained angular data with that measured using five goniophotometers of different types.

Lipid droplets (LDs) are intracellular lipid-storing organelles surrounded by a phospholipid monolayer. LDs emerge as metabolically active organelles involved in many biological processes and linked to the pathogenesis of several dysfunctions including metabolic diseases (obesity, diabetes, atherosclerosis and hepatic steatosis). The mechanism underlying LD formation is still poorly understood and the molecular players that take part in this process have to be identified. Here, we provide evidence that a member of the C-terminal binding protein (CtBP) family, CtBP1-S/BARS (for brevity BARS), associates with LDs and is necessary for their formation. BARS is a fission-inducing protein that regulates several membrane trafficking events. Since the widely accepted model regarding LD biogenesis describes the formation of these organelles as fission products from specific endoplasmic reticulum microdomains, we wondered whether BARS could play a role in this process. We show that BARS is highly expressed during 3T3-L1 adipocytes cell differentiation. Interestingly, either the depletion or the inhibition of BARS strongly reduced the number of LD with an increased their size (in several tested cell types), indicating a central role of BARS in LD biogenesis. Furthermore, we found that BARS interacts and activates Acyl-CoA:lysocardiolipin acyltransferase (LCLAT1/AGPAT8) that catalyses the acylation of lysophosphatidilinositol (LPI) into phosphatidylinositol (PI), one of the main LD surface phospholipid component. Interestingly, we demonstrate that both BARS and AGPAT8 are recruited onto LDs where they interact and their specific LD membrane targeting is required for proper LD biogenesis. Our results shed new light on mechanisms underlying neutral lipid storage and highlight BARS and its binding partner AGPAT8 as key regulators in the biogenesis of lipid droplets.

Lipid droplets (LDs) are intracellular lipid-storing organelles surrounded by a phospholipid monolayer. LDs emerge as metabolically active organelles involved in many biological processes and linked to the pathogenesis of several dysfunctions including metabolic diseases (obesity, diabetes, atherosclerosis and hepatic steatosis). The mechanism underlying LD formation is still poorly understood and the molecular players that take part in this process have to be identified. Here, we provide evidence that a member of the C-terminal binding protein (CtBP) family, CtBP1-S/BARS (for brevity BARS), associates with LDs and is necessary for their formation. BARS is a fission-inducing protein that regulates several membrane trafficking events. Since the widely accepted model regarding LD biogenesis describes the formation of these organelles as fission products from specific endoplasmic reticulum microdomains, we wondered whether BARS could play a role in this process. We show that BARS is highly expressed during 3T3-L1 adipocytes cell differentiation. Interestingly, either the depletion or the inhibition of BARS strongly reduced the number of LD with an increased their size (in several tested cell types), indicating a central role of BARS in LD biogenesis. Furthermore, we found that BARS interacts and activates Acyl-CoA:lysocardiolipin acyltransferase (LCLAT1/AGPAT8) that catalyses the acylation of lysophosphatidilinositol (LPI) into phosphatidylinositol (PI), one of the main LD surface phospholipid component. Interestingly, we demonstrate that both BARS and AGPAT8 are recruited onto LDs where they interact and their specific LD membrane targeting is required for proper LD biogenesis. Our results shed new light on mechanisms underlying neutral lipid storage and highlight BARS and its binding partner AGPAT8 as key regulators in the biogenesis of lipid droplets.

The chromosome 9p21 amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) locus contains one of the last major unidentified autosomal-dominant genes underlying these common neurodegenerative diseases. We have previously shown that a founder haplotype, covering the MOBKL2b, IFNK, and C9ORF72 genes, is present in the majority of cases linked to this region. Here we show that there is a large hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72 on the affected haplotype. This repeat expansion segregates perfectly with disease in the Finnish population, underlying 46.0% of familial ALS and 21.1% of sporadic ALS in that population. Taken together with the D90A SOD1 mutation, 87% of familial ALS in Finland is now explained by a simple monogenic cause. The repeat expansion is also present in one-third of familial ALS cases of outbred European descent, making it the most common genetic cause of these fatal neurodegenerative diseases identified to date. © 2011 Elsevier Inc.

Desmosterol is an immediate precursor of cholesterol in the Bloch pathway of sterol synthesis and an abundant membrane lipid in specific cell types. The significance of the difference between the two sterols, an additional double bond at position C24 in the tail of desmosterol, is not known. Here, we provide evidence that the biophysical and functional characteristics of the two sterols differ and that this is because the double bond at C24 significantly weakens the sterol ordering potential. In model membranes, desmosterol was significantly weaker than cholesterol in promoting the formation or stability of ordered domains, and in mammalian cell membranes, desmosterol associated less avidly than cholesterol with detergent-resistant membranes. Atomic scale molecular dynamics simulations showed that the double bond gives rise to additional stress in the tail, creating a rigid structure between C24 and C27 and favoring tilting of desmosterol distinct from cholesterol. Functional effects of desmosterol in cell membranes were assessed upon acutely exchanging ~70% of cholesterol to desmosterol. This led to impaired raft-dependent signaling via the insulin receptor, whereas non-raft-dependent protein secretion was not affected. We suggest that the choice of cholesterol synthesis route may provide a physiological mechanism to modulate raft-dependent functions in cells.

We use the Semliki Forest Virus (SFV) as a tool for protein expression in primary cultures of rat hippocampal neurons. These cells develop in vitro into polarized neurons that can be infected with recombinant SFV with an efficiency of 60 - 80%. SFV-driven protein expression is detectable within 3-4 hours postinfection, at which time the newly-synthesized proteins are mainly present in the cell soma. By 6 to 8 hours postinfection foreign proteins are detectable in the neurites. Protein expression can continue for up to 48 hours. However, after 8 - 10 hours infected neurons start to suffer from cytopathic effects as evidenced by a change in morphology and detachment from the coverslip. The infection does not seem to affect the polarized distribution of proteins. Upon overexpression of rab8, a somatodendritic distribution is observed, similar to that of the endogenous protein. Therefore, the SFV expression system is suitable for short-term expression of proteins and can be used successfully to study the polarized distribution of heterologous proteins expressed in cultured hippocampal neurons.

Isotropic powders and magnetically aligned crystallites of EuBa2Cu3O7−δ (1:2:3) and europium-doped Bi2Sr2CaCu2O8 (2:2:1:2) were studied by means of x-ray diffraction and Eu151 Mössbauer spectroscopy. The degree of crystallite orientation of the samples and the values of the lattice constants were determined by x-ray diffraction. The Mössbauer spectra were analyzed considering the full hyperfine Hamiltonian of the nuclear states of the 21.5-keV γ transition. The Mössbauer hyperfine parameters obtained from the superconducting and semiconducting phases are presented. A small change is seen in the Eu151 isomer shift when the oxygen deficiency δ of the 1:2:3 compound is varied. The shift can be explained by a decrease in the s-electron density due to lattice expansion. The changes in the oxidation state of the copper atoms with varying δ were determined from the Mössbauer data: The Cu(2) atoms retain their oxidation state, whereas the Cu(1) atoms adjust their valence according to the value of δ. In the 2:2:1:2 samples, the Eu concentration clearly affected the value of the electric-field gradient at the Eu nucleus. Using a standard procedure, magnetically aligned 2:2:1:2 samples were prepared. The preferred direction of the crystal c axis changed from parallel to perpendicular alignment with the external magnetic field, when the Eu concentration exceeded 20% of the Ca atoms.

The question about heterogeneity of Huntington disease (HD) at the DNA level can be approached by analyzing the RFLP haplotypes formed by several RFLP loci of the diseased chromosome in different populations. In genetically isolated populations such as Finland, it is further possible to use this approach to test the hypothesis of a single mutation enriched in this population demonstrating an exceptionally low prevalence of HD. In this study covering 70% of all diagnosed HD cases in Finland, linkage disequilibrium of RFLP haplotypes of D4S10 and D4S43 loci polymorphisms was found. This phenomenon, not so far reported in any other population, could support the hypothesis of one ancestor HD mutation in the Finnish population. Despite the lower heterozygosity obtained with some RFLP markers, the proportion of individuals receiving informative DNA test results did not significantly differ from that reported in more mixed populations. In one HD family we established a recombination event between HD and the D4S43 locus, an event which can be highly useful in the more precise mapping of the HD gene.

In the international Baltic Sea trout tagging experiment 27 753 hatchery reared sea trout smolts were tagged in Denmark, Finland, Poland and Sweden in 1979 and 1980. The fish were tagged with the original Carlin tag, two modified Carlin tag types (Canadian and Finnish polythene), streamer and Floy tags and Polish tags attached with Monel metal wire. The tag returns were affected by the placeof release and smolt quality. The best results were obtained in the case of tags attached with double wire or thread -original Carlin, Canadian and Finnish polythene. The poorest results were obtained with streamer tags. Environment Agency Archives North West

Publication in the conference proceedings of EUSIPCO, Poznan, Poland, 2007

Biological processes are inherently continuous, and the chance of phenotypic discovery is significantly restricted by discretising them. Using multi-parametric active regression we introduce the Regression Plane (RP), a user-friendly discovery tool enabling class-free phenotypic supervised machine learning, to describe and explore biological data in a continuous manner. First, we compare traditional classification with regression in a simulated experimental setup. Second, we use our framework to identify genes involved in regulating triglyceride levels in human cells. Subsequently, we analyse a time-lapse dataset on mitosis to demonstrate that the proposed methodology is capable of modelling complex processes at infinite resolution. Finally, we show that hemocyte differentiation in Drosophila melanogaster has continuous characteristics., High-content screening prompted the development of software enabling discrete phenotypic analysis of single cells. Here, the authors show that supervised continuous machine learning can drive novel discoveries in diverse imaging experiments and present the Regression Plane module of Advanced Cell Classifier.

Summary Systematic insight into cellular dysfunction can improve understanding of disease etiology, risk assessment, and patient stratification. We present a multiparametric high-content imaging platform enabling quantification of low-density lipoprotein (LDL) uptake and lipid storage in cytoplasmic droplets of primary leukocyte subpopulations. We validate this platform with samples from 65 individuals with variable blood LDL-cholesterol (LDL-c) levels, including familial hypercholesterolemia (FH) and non-FH subjects. We integrate lipid storage data into another readout parameter, lipid mobilization, measuring the efficiency with which cells deplete lipid reservoirs. Lipid mobilization correlates positively with LDL uptake and negatively with hypercholesterolemia and age, improving differentiation of individuals with normal and elevated LDL-c. Moreover, combination of cell-based readouts with a polygenic risk score for LDL-c explains hypercholesterolemia better than the genetic risk score alone. This platform provides functional insights into cellular lipid trafficking and has broad possible applications in dissecting the cellular basis of metabolic disorders.

Integrated control and process design (ICPD) was implemented for circulating fluidized bed power plants (CFB) in this thesis to obtain fast electrical power load changes. The need to reduce global emissions has resulted in new design requirements for CFB boilers: Combustion power plants are needed for fast load changes due to renewable power variations, and process modifications like oxy-combustion have to be implemented for CFB boilers. This thesis addressed the new requirements by integrating control design with process design for CFB boilers, which was done now for the first time. The work defined an ICPD procedure for closed-loop CFB processes that focuses on load change performance. This was done by reviewing and classifying ICPD literature to select suitable design and analysis methods. The new ICPD procedure consisted of process analysis based on dynamic simulation and state estimation, control structure selection based on relative gain methods, and simultaneous dynamic optimization of process and controller parameters. The design stages were validated through industrial case studies. In the process analysis stage, CFB combustion and flue gas dynamics were studied to define how the boiler should be modified for oxy-combustion. In the control design stage, the relative gain methods were used to identify feasible control structures and performance-limiting interactions in a once-through CFB boiler. In the ICPD optimization stage, the CFB steam path mass storage parameters and controllers were optimized for simulated load change ramps. The goal was to achieve tight output electrical power control and satisfy selected secondary control objectives. The results show how faster load changes and a better flexibility for process modifications are obtained through ICPD compared to sequential process and control design. The design guidelines presented in this thesis thus enable more sustainable power generation in the grid. Tiivistelmä Tässä väitöstutkimuksessa sovellettiin integroitua säätö- ja prosessisuunnittelua (ICPD) kiertoleijupetivoimalaitoksiin (CFB) nopeiden sähkön kuormanmuutosten saavuttamiseksi. Globaalien päästöjen vähentämisen tarve on asettanut uusia suunnitteluvaatimuksia CFB-kattiloille: Uusiutuvan energiantuotannon vaihteluiden vuoksi polttovoimalaitoksia tarvitaan nopeita kuormanmuutoksia varten ja happipolton kaltaisia prosessimuunnoksia on sovellettava CFB-kattiloille. Uusista vaatimuksista johtuviin haasteisiin väitöstutkimus vastasi integroimalla säätö- ja prosessisuunnittelua CFB-kattiloille. Näin tehtiin nyt ensimmäistä kertaa. Työssä määritettiin suljetun piirin CFB-prosesseille kuormanmuutosten suorituskykyä painottava ICPD-suunnittelumalli. Tämä suoritettiin tarkastelemalla ja luokittelemalla ICPD-kirjallisuutta sopivien suunnittelu- ja analyysimenetelmien valitsemiseksi. ICPD-suunnittelumalli koostui dynaamiseen simulointiin ja tilaestimointiin perustuvasta prosessianalyysista, suhteellisen vahvistuksen menetelmiin (”relative gain”) perustuvasta säätörakenteen valinnasta sekä prosessin ja säädinten parametrien yhtäaikaisesta dynaamisesta optimoinnista. Suunnitteluvaiheet validoitiin teollisten tutkimusesimerkkien kautta. CFB:n poltto- ja savukaasudynamiikkaa tutkittiin prosessianalyysivaiheessa, tarkoituksena määrittää, kuinka kattilaa tulisi muuntaa happipolttoa varten. Säätörakenteen valintavaiheessa suhteellisen vahvistuksen menetelmiä käytettiin läpivirtaus-CFB-kattilalle soveltuvien säätörakenteiden ja suorituskykyä rajoittavien vuorovaikutusten määrittämiseen. CFB:n höyrypuolen massavarantoparametrit ja säätimet optimoitiin simuloiduille kuormarampeille ICPD-optimointivaiheessa. Tavoitteena oli saavuttaa tarkka tuotettavan sähkön säätö sekä valitut toissijaiset säätötavoitteet. Tulokset osoittavat, miten ICPD:n kautta saavutetaan nopeampia kuormanmuutoksia ja parempi joustavuus prosessimuutosten osalta vaiheittaiseen prosessi- ja säätösuunnitteluun verrattuna. Työssä esitetyt CFB-kattiloiden suunnittelukäytännöt mahdollistavat täten ympäristöystävällisemmän voimantuotannon verkossa.

Energy production in combustion power plants is a significant source of anthropogenic carbon dioxide emissions. The targets of international climate agreements call for utilizing all available technologies to achieve rapid and cost-effective emission reductions. Carbon capture and storage is one of the possible technical solutions applied in combustion power plants. Circulating fluidized bed boilers have gained increasing popularity due to advantages in availability, emission control, fuel flexibility and option for using challenging fuels, and the possibility of using high-efficiency steam cycles. In the novel process of oxy-combustion, combustion air is replaced by a mixture of oxygen and recycled flue gas to facilitate the capture of carbon dioxide from the flue gas flow. Additional degrees of freedom become available for combustion control as the gas flow and composition can be controlled separately for fluidization and combustion purposes. In the research for this thesis, self-optimizing control was applied for the control structure design of a circulating fluidized bed boiler. Self-optimizing control offers a systematic tool for the early phases of control design, in which decisions have traditionally been made based on intuition, heuristics and previous experience. The self-optimizing control approach searches for controlled variables without a need for constant setpoint optimization when the process is affected by disturbances and implementation errors. Results presented in the thesis show that self-optimizing control can be applied in the control structure design of circulating fluidized bed combustion. A range of control structure alternatives were evaluated using steady-state approximations of a validated process model. For the novel oxy-combustion process, promising control structures were identified and could be dynamically demonstrated. Tiivistelmä Energiantuotanto polttovoimalaitoksissa on merkittävä hiilidioksidipäästöjen lähde. Kansainväliset ilmastotavoitteet edellyttävät kaikkien käytettävissä olevien teknologioiden hyödyntämistä päästövähennysten aikaansaamiseksi nopeasti ja kustannustehokkaasti. Hiilidioksidin talteenotto on yksi mahdollisista teknisistä ratkaisuista polttovoimalaitoksissa. Kiertoleijukattilat ovat saavuttaneet kasvavaa suosiota etuinaan hyvä käytettävyys, tehokas päästöjen hallinta, soveltuvuus erilaisten haastavienkin polttoaineiden hyödyntämiseen ja mahdollisuus tehokkaiden höyrykiertojen käyttöön. Uudessa happipolttoprosessissa palamisilma korvataan hapen ja kierrätetyn savukaasun seoksella, mikä mahdollistaa hiilidioksidin talteenoton savukaasuista. Kiertoleijupolton säädön kannalta vapausasteet lisääntyvät, sillä leijutukseen ja polttamiseen käytettävän kaasun määrää ja koostumusta voidaan säätää erikseen. Väitöstutkimuksessa käytettiin itseoptimoivaa säätöä kiertoleijukattilan säätörakenteiden suunnitteluun. Itseoptimoiva säätö tarjoaa systemaattisen menetelmän säätösuunnittelun alkuvaiheeseen, jossa päätöksenteko on perinteisesti tehty esimerkiksi intuition, heuristiikan ja aiempien ratkaisujen perusteella. Menetelmän tavoitteena on löytää säädettävät muuttujat, joiden asetusarvot eivät vaadi jatkuvaa optimointia, vaikka prosessiin vaikuttavat erilaiset häiriöt ja mittausvirheet. Väitöstutkimuksen tulokset osoittavat, että itseoptimoiva säätö soveltuu kiertoleijupolton säätörakenteiden suunnitteluun. Erilaisten säätörakenteiden toimivuutta arvioitiin käyttäen validoidun prosessimallin tasapainotilan approksimaatioita. Uudelle happipolttoprosessille löydettiin lupaavia säätörakenteita, joiden toimintaa voitiin demonstroida myös dynaamisesti.

This thesis deals with the pump schedule optimisation of regional water distribution systems. The aims and the possible applications of the presented methods differ from each other; all of them are intended to solve a particular but realistic problem. The developed techniques use the capacity of the water reservoirs in order to find the optimal pump-schedule of the system. The optimisation task is always deterministic and discrete in time; the stochastic behaviour of the water consumptions is approximated by expected values. A so-called neutral genetic algorithm equipped with new constraint handling is presented first. The method is able to solve the scheduling problems of real-size and complex networks, e.g. the network of Budapest with coupled hydraulic simulations where both variable and fixed speed pumps are in the network. The results are compared to other ones obtained by widely used genetic algorithms and state-of-the-art general purpose optimisation solvers. A dynamic programming based method was also carried out which provides the global optimum of the so-called ’combinatorial’ pump scheduling problems. This modelling type is very common in the industry, which can be used if the operation points of the pumps take discrete values. The basic idea of the method is exploiting the ’permutational invariance’ of the model which results in a perfect discretisation of the state space without any loss of information. An approximate dynamic programming technique is also presented which solves the same type of problems as the formerly mentioned genetic algorithm does. The technique splits the water network model into smaller units, namely into the so-called well fields and the main distribution system. The state space of the main distribution system was further decreased while the quality of the results does not decay. A part of the test examples is the same as in the case of the former presented genetic algorithm; thus, the two methods can be compared. Finally, a small water network fed by a single variable speed pump was investigated. The presented methods are based on the minimisation of the specific energy consumption. The gained results are compared to ones obtained using a high-resolution discrete dynamic program. Novel optimisation techniques for water distribution network pump scheduling were developed in this work. A particular focus was put on the dynamics between pumping, water reservoirs, and water use. The work shows the applicability of the approach via numerous realistic simulation case studies. Tiivistelmä Työ käsittelee alueellisten vedenjakelujärjestelmien pumppauksen aikataulutuksen optimointia. Esitettyjen menetelmien tavoitteet ja mahdolliset sovellukset poikkeavat toisistaan. Kaikki on kuitenkin tarkoitettu tiettyjen todellisten ongelmien ratkaisemiseen. Kehitetyt tekniikat käyttävät vesivarastojen kapasiteettia optimaalisen pumppausohjelman löytämiseksi. Jokainen optimointitehtävä on aikadiskreetti ja deterministinen, vedenkulutuksen stokastista käyttäytymistä on approksimoitu odotusarvoilla. Ensimmäiseksi työssä esitetään ns. neutraaleja geneettisiä algoritmeja varustettuna rajoitusten käsittelyllä. Menetelmällä voidaan ratkaista skedulointiohjelmia reaalimittakaavaisille ja monimutkaisille verkostoille (esim. Budapestin verkosto varustettuna hydraulisilla simuloinneilla, sekä muuttuvanopeuksisilla että vakionopeuksisilla verkoston pumpuilla). Tuloksia verrataan toisiin yleisesti käytössä olevilla geneettisillä algoritmeilla saatuihin, sekä johtavilla yleiskäyttöisillä optimointitekniikoilla saatuihin tuloksiin. Työssä käytettiin myös dynaamiseen ohjelmointiin pohjaavaa menetelmää, jolla saadaan globaali optimi ns. "kombinatoorisille" pumppauksen aikataulutusongelmille. Tällainen mallinnustapa on hyvin yleistä teollisuudessa. Sitä voidaan käyttää, jos pumppujen toimintapisteet saavat diskreettejä arvoja. Menetelmän perusajatuksena on "permutationaalisen invarianssin" hyväksikäyttäminen, josta seuraa tila-avaruuden virheetön diskretointi ilman informaation häviämistä. Työssä esitellään myös approksimoidun dynaamisen ohjelmoinnin tekniikka, jonka avulla voidaan ratkaista samantyyppisiä ongelmia kuin yllämainituilla geneettisillä algoritmeilla. Tämä tekniikka jakaa vesijohtoverkoston mallin pienempiin yksiköihin: lähdekenttiin ja pääjakeluverkostoon. Pääjakeluverkoston tila-avaruutta voitiin edelleen pienentää ilman, että tulosten laatu heikkeni. Osa käsitellyistä esimerkkitapauksista on samoja kuin edellämainittujen geneettisten algoritmien osalla, joten tuloksia voidaan verrata. Lopuksi tutkittiin pienen muuttuvanopeuksisella pumpulla syötetyn vesijohtoverkoston toimintaa. Esitetyt menetelmät perustuvat ominaisenergiankulutuksen minimointiin. Saatuja tuloksia verrataan korkearesoluutioisella diskreetillä dynaamisella ohjelmoinnilla saatuihin tuloksiin. Työssä kehitettiin uusia optimointitekniikoita vedenjakelujärjestelmien pumppauksen aikataulutuksen optimintiin. Erityisesti työssä keskityttiin pumppauksen, vesitornien ja kuluttajien käyttäytymisen väliseen dynamiikkaan. Työssä osoitettiin tekniikoiden toimivuus realististen esimerkkisimulointien avulla. Kivonat Jelen doktori disszertáció regionális ivóvízellátó-hálózatok üzemvitel-optimalizációjával foglalkozik. A bemutatott módszerek alkalmazhatósági köre rendszerint eltér egymástól, mindegyik egy-egy speciális, de a való életben is előforduló problémára kíván megoldást nyújtani. A kidolgozott módszerek a medencék tárolókapacitását kihasználva, az optimális szivattyú-menetrendet keresve kívánják megtalálni az adott vízműhálózat üzemviteloptimumát. Az optimalizáció egy időben diszkrét, ugyanakkor determinisztikus feladat megoldását igényli, a vízfogyasztások sztochasztikus viselkedését a várható értékekkel közelítettem. Elsőként egy új mellékfeltétel-kezeléssel ellátott, ún. neutrális genetikus algoritmus bemutatása a cél. A kidolgozott módszer alkalmas nagy, valós méretű (pl. Budapest) és bonyolultságú (kapcsolt hidraulikai szimulációk, frekvenciaváltós és direkt szivattyúk a hálózatban) ivóvízhálózatok napi üzemvitel optimalizálására. Az eredményeket más genetikus algoritmusokkal és a világ élvonalába tartozó, de általános célú optimalizációs módszerekkel hasonlítottam össze. Kidolgozásra került egy dinamikus programozás alapú, a valós, globális optimumot adó módszer is. Az algoritmus a gyakorlatban elterjedt, ún. "kombinációs" hálózatként modellezhető vízműhálózat típusokra alkalmazható, ahol a szivattyúk munkapontjai diszkrét értékek. A megoldás alapját az ún. "permutációs invariancia" jelensége adja, mely lehetővé teszi az állapottér információveszteség nélküli, tökéletes diszkretizációját. Egy, a korábban bemutatott genetikus algoritmuséhoz hasonló problémakört megoldó, de közelítő dinamikus programozás alapú módszer is bemutatásra kerül. Az algoritmus a hálózat kisebb részegységekre (víztermelő területekre és fő elosztó hálózatra) való felbontásával és a fő elosztó hálózat állapotterének önkényes, de a megoldás jóságán jelentősen nem rontó csökkentésével éri el a program futtatásához szükséges számítási igény csökkentését. A tesztfeladatok egy része megegyezik a genetikus algoritmus tesztfeladataival, így azok közvetlenül összehasonlíthatóak. Végül bemutatásra kerül egy kisméretű, mindössze egy darab változtatható fordulat- számú szivattyúval táplált rendszer energetikai vizsgálata. Az itt bemutatott módszerek mind a fajlagos energiafelhasználás minimalizálásán alapulnak. Az eredményeket egy nagyfelbontású dinamikus programozás alapú módszerhez hasonlítottam.