Ultrafine grinding of FGD and phosphogypsum with an attrition bead mill and a jet mill : optimisation and modelling of grinding and mill comparison

Fine powders of minerals are used commonly in the paper and paint industry, and for ceramics. Research for utilizing of different waste materials in these applications is environmentally important. In this work, the ultrafine grinding of two waste gypsum materials, namely FGD (Flue Gas Desulphurisation) gypsum and phosphogypsum from a phosphoric acid plant, with the attrition bead mill and with the jet mill has been studied. The ' objective of this research was to test the suitability of the attrition bead mill and of the jet mill to produce gypsum powders with a particle size of a few microns. The grinding conditions were optimised by studying the influences of different operational grinding parameters on the grinding rate and on the energy consumption of the process in order to achieve a product fineness such as that required in the paper industry with as low energy consumption as possible. Based on experimental results, the most influential parameters in the attrition grinding were found to be the bead size, the stirrer type, and the stirring speed. The best conditions, based on the product fineness and specific energy consumption of grinding, for the attrition grinding process is to grind the material with small grinding beads and a high rotational speed of the stirrer. Also, by using some suitable grinding additive, a finer product is achieved with a lower energy consumption. In jet mill grinding the most influential parameters were the feed rate, the volumetric flow rate of the grinding air, and the height of the internal classification tube. The optimised condition for the jet is to grind with a small feed rate and with a large rate of volumetric flow rate of grinding air when the inside tube is low. The finer product with a larger rate of production was achieved with the attrition bead mill than with the jet mill, thus the attrition grinding is better for the ultrafine grinding of gypsum than the jet grinding. Finally the suitability of the population balance model for simulation of grinding processes has been studied with different S , B , and C functions. A new S function for the modelling of an attrition mill and a new C function for the modelling of a jet mill were developed. The suitability of the selected models with the developed grinding functions was tested by curve fitting the particle size distributions of the grinding products and then comparing the fitted size distributions to the measured particle sizes. According to the simulation results, the models are suitable for the estimation and simulation of the studied grinding processes.

Development of Color Difference Equations Matching to Human Vision System

Research on color difference evaluation has been active in recent thirty years. Several color difference formulas were developed for industrial applications. The aims of this thesis are to develop the color density which is denoted by comb g and to propose the color density based chromaticity difference formulas. Color density is derived from the discrimination ellipse parameters and color positions in the xy , xyY and CIELAB color spaces, and the color based chromaticity difference formulas are compared with the line element formulas and CIE 2000 color difference formulas. As a result of the thesis, color density represents the perceived color difference accurately, and it could be used to characterize a color by the attribute of perceived color difference from this color.

MCMC Analysis Of Classical Time Series Algorithms

Identification of order of an Autoregressive Moving Average Model (ARMA) by the usual graphical method is subjective. Hence, there is a need of developing a technique to identify the order without employing the graphical investigation of series autocorrelations. To avoid subjectivity, this thesis focuses on determining the order of the Autoregressive Moving Average Model using Reversible Jump Markov Chain Monte Carlo (RJMCMC). The RJMCMC selects the model from a set of the models suggested by better fitting, standard deviation errors and the frequency of accepted data. Together with deep analysis of the classical Box-Jenkins modeling methodology the integration with MCMC algorithms has been focused through parameter estimation and model fitting of ARMA models. This helps to verify how well the MCMC algorithms can treat the ARMA models, by comparing the results with graphical method. It has been seen that the MCMC produced better results than the classical time series approach.

Polymeeripinnoitteen aiheuttamat itseherätteiset värähtelyt nipillisessä telasysteemissä

Lukuisissa teollisuussovelluksissa materiaalien, kuten paperin ja teräslevyjen, muokkaamiseen käytettävät pyörivät nippitelat kärsivät aina erilaisten herätteiden synnyttämistä mekaanisista värähtelyistä, jotka voivat aiheuttaa virheitä valmistettaviin tuotteisiin. Tässä työssä tutkittiin viskoelastisia polymeerejä ja polymeeripinnoitteen nipilliseen telasysteemiin synnyttämiä haitallisia itseherätteisiä värähtelyjä. Työn polymeerejä käsittelevässä kirjallisuusosassa luotiin katsaus amorfisten polymeerien fysikaalisiin ominaisuuksiin. Kokeellisessa osuudessa tutkittiin tarkemmin kahden amorfisen telapinnoitepolymeerin termoreologisia ja mekaanisia ominaisuuksia suoritettujen DMTA-mittausten perusteella. Sovittamalla toisen polymeerin master-käyrään yleistetty lineaarisen standardiaineen malli saatiin selville polymeerin mekaaniset parametrit ja approksimaatio sen relaksaatiospektrille. Telapinnoitteen nipilliseen systeemiin synnyttämiä itseherätteisiä värähtelyjä ja niiden seurauksia tarkasteltiin kahdelle telalle ja polymeeripinnoitteelle kehitetyn analyyttisen mallin ja numeeristen laskujen avulla. Pinnoite mallinnettiin lineaarisen standardiaineen mukaisesti. Telasysteemin parametrit määritettiin DMTA-mittaustuloksista ja systeemiä vastaavasta koelaitteesta kokeellisella moodianalyysillä ja elementtimenetelmällä. Numeerisesta stabiilisuusanalyysistä ja liikeyhtälöiden integroinneista saadut tulokset kertovat telapinnoitteen aaltomaisista deformaatiomuodoista ja niiden synnyttämistä taajuusalueittain esiintyvistä epästabiileista värähtelyistä. Telasysteemi on epästabiili pinnoitedeformaatiokuvion systeemiin aiheuttaman herätevoiman taajuuden ollessa lähellä systeemin korkeampaa ominaistaajuutta. Numeerisista tuloksista voitiin ennustaa nopean ja hitaan barringin olemassaolo.

Kinetic modeling of mechanisms of industrially important organic reactions in gas and liquid phase

This dissertation is based on 5 articles which deal with reaction mechanisms of the following selected industrially important organic reactions: 1. dehydrocyclization of n-butylbenzene to produce naphthalene 2. dehydrocyclization of 1-(p-tolyl)-2-methylbutane (MB) to produce 2,6-dimethylnaphthalene 3. esterification of neopentyl glycol (NPG) with different carboxylic acids to produce monoesters 4. skeletal isomerization of 1-pentene to produce 2-methyl-1-butene and 2-methyl-2-butene The results of initial- and integral-rate experiments of n-butylbenzene dehydrocyclization over selfmade chromia/alumina catalyst were applied when investigating reaction 2. Reaction 2 was performed using commercial chromia/alumina of different acidity, platina on silica and vanadium/calcium/alumina as catalysts. On all catalysts used for the dehydrocyclization, major reactions were fragmentation of MB and 1-(p-tolyl)-2-methylbutenes (MBes), dehydrogenation of MB, double bond transfer, hydrogenation and 1,6-cyclization of MBes. Minor reactions were 1,5-cyclization of MBes and methyl group fragmentation of 1,6- cyclization products. Esterification reactions of NPG were performed using three different carboxylic acids: propionic, isobutyric and 2-ethylhexanoic acid. Commercial heterogeneous gellular (Dowex 50WX2), macroreticular (Amberlyst 15) type resins and homogeneous para-toluene sulfonic acid were used as catalysts. At first NPG reacted with carboxylic acids to form corresponding monoester and water. Then monoester esterified with carboxylic acid to form corresponding diester. In disproportionation reaction two monoester molecules formed NPG and corresponding diester. All these three reactions can attain equilibrium. Concerning esterification, water was removed from the reactor in order to prevent backward reaction. Skeletal isomerization experiments of 1-pentene were performed over HZSM-22 catalyst. Isomerization reactions of three different kind were detected: double bond, cis-trans and skeletal isomerization. Minor side reaction were dimerization and fragmentation. Monomolecular and bimolecular reaction mechanisms for skeletal isomerization explained experimental results almost equally well. Pseudohomogeneous kinetic parameters of reactions 1 and 2 were estimated by usual least squares fitting. Concerning reactions 3 and 4 kinetic parameters were estimated by the leastsquares method, but also the possible cross-correlation and identifiability of parameters were determined using Markov chain Monte Carlo (MCMC) method. Finally using MCMC method, the estimation of model parameters and predictions were performed according to the Bayesian paradigm. According to the fitting results suggested reaction mechanisms explained experimental results rather well. When the possible cross-correlation and identifiability of parameters (Reactions 3 and 4) were determined using MCMC method, the parameters identified well, and no pathological cross-correlation could be seen between any parameter pair.

Automated, adaptive methods for forest inventory

Forest inventories are used to estimate forest characteristics and the condition of forest for many different applications: operational tree logging for forest industry, forest health state estimation, carbon balance estimation, land-cover and land use analysis in order to avoid forest degradation etc. Recent inventory methods are strongly based on remote sensing data combined with field sample measurements, which are used to define estimates covering the whole area of interest. Remote sensing data from satellites, aerial photographs or aerial laser scannings are used, depending on the scale of inventory. To be applicable in operational use, forest inventory methods need to be easily adjusted to local conditions of the study area at hand. All the data handling and parameter tuning should be objective and automated as much as possible. The methods also need to be robust when applied to different forest types. Since there generally are no extensive direct physical models connecting the remote sensing data from different sources to the forest parameters that are estimated, mathematical estimation models are of "black-box" type, connecting the independent auxiliary data to dependent response data with linear or nonlinear arbitrary models. To avoid redundant complexity and over-fitting of the model, which is based on up to hundreds of possibly collinear variables extracted from the auxiliary data, variable selection is needed. To connect the auxiliary data to the inventory parameters that are estimated, field work must be performed. In larger study areas with dense forests, field work is expensive, and should therefore be minimized. To get cost-efficient inventories, field work could partly be replaced with information from formerly measured sites, databases. The work in this thesis is devoted to the development of automated, adaptive computation methods for aerial forest inventory. The mathematical model parameter definition steps are automated, and the cost-efficiency is improved by setting up a procedure that utilizes databases in the estimation of new area characteristics.

Väriavaruuden rakenteen muokkaaminen yhtenäisyyden parantamiseksi

Pienien värierojen mittaamiseen käytetään CIE:n (The International Commission on Illumination) kehittämää ja standardoitua CIELAB – väriavaruutta ja sille suunniteltua CIEDE2000 – värieromittaria. CIELAB ei kuitenkaan ole täysin yhtenäinen ja siksi mittareita joudutaan virittämään sopivammiksi tähän väriavaruuteen. Työssä tutkitaan millä tavoin CIELAB - väriavaruutta voitaisiin korjata, jotta siitä saataisiin yhtenäisempi ja yksinkertainen ja virittämättömämpi värieromittari toimisi siinä paremmin. Työn tuloksena saatu muokattu väriavaruus paransi yhtenäisyyttä keskimäärin kymmenen prosenttia, mikä on liian vähän kun tavoitteena oli 30 - 50 prosenttia.

Identification of Epigenetic Targets in Prostate Cancer for Therapeutic Development

Recurrent castration resistant prostate cancer remains a challenge for cancer therapies and novel treatment options in addition to current anti-androgen and mitosis inhibitors are needed. Aberrations in epigenetic enzymes and chromatin binding proteins have been linked to prostate cancer and they may form a novel class of drug targets in the future. In this thesis we systematically evaluated the epigenenome as a prostate cancer drug target. We functionally silenced 615 known and putative epigenetically active protein coding genes in prostate cancer cell lines using high throughput RNAi screening and evaluated the effects on cell proliferation, androgen receptor (AR) expression and histone patterns. Histone deacetylases (HDACs) were found to regulate AR expression. Furthermore, HDAC inhibitors reduced AR signaling and inhibited synergistically with androgen deprivation prostate cancer cell proliferation. In particular, TMPRSS2- EGR fusion gene positive prostate cancer cell lines were sensitive to combined HDAC and AR inhibition, which may partly be related to the dependency of a fusion gene induced epigenetic pathway. Histone demethylases (HDMs) were identified to regulate prostate cancer cell line proliferation. We discovered a novel histone JmjC-domain histone demethylase PHF8 to be highly expressed in high grade prostate cancers and mediate cell proliferation, migration and invasion in in vitro models. Additionally, we explored novel HDM inhibitor chemical structures using virtual screening methods. The structures best fitting to the active pocket of KDM4A were tested for enzyme inhibition and prostate cancer cell proliferation activity in vitro. In conclusion, our results show that prostate cancer may efficiently be targeted with combined AR and HDAC inhibition which is also currently being tested in clinical trials. HDMs were identified as another feasible novel drug target class. Future studies in representative animal models and development of specific inhibitors may reveal HDMs full potential in prostate cancer therapy

Applications of augmented reality for sales in apparel industry in Russia

The sustainable growth of video interactivity technologies on different platforms in the lasts years opens good prospects for augmented reality technology adoption on different markets. In the end of 2011 there was an improvement in technology which allows building the 3D model of human body. Such an improvement could be used in apparel industry. The main goal of the study is to understand the level of acceptance of augmented reality as a technology on the Russian apparel market. For a more accurate investigation, a new model accounting for augmented reality characteristics, as well as for similarities and differences between online and offline customer behavior in apparel industry, was developed. As a result of the survey, the weights of different purchase intention factors for Russian consumer were found, and the information about Russian consumers’ preferences towards the augmented reality features in apparel market, especially in fitting time, real-time interaction and fitting quality peculiarities, was presented.

Applying Qt to programming courses

Työn tavoitteena on sovittaa Qt opetussuunnitelmaan. Työ sisältää Qt:n lyhyen historian sekä katsauksen sen nykytilaan. Nykytilakatsaus sisältää kolme näkökulmaa: miten ja missä Qt:ta voidaan käyttää, sekä sen käyttötarkoitukset teollisuudessa ja opetuksessa. Työn tuloksena syntyy luentodemonstraatiota varten pieni ohjelma, joka on luotu C++:n ja Qt Designerin avulla ja käyttää olennaisia käyttöliittymäkirjaston olioita. Toisena tuotteena työssä syntyy luonnos Lappeenrannan Teknillisen Yliopiston ohjelmointikursseista, joissa Qt:ta voitaisiin käyttää avustamaan opiskelijoita näkemään, miten graafinen ohjelma luodaan sekä valmentaa heitä ymmärtämään viitekehyksien ja graafisten kirjastojen tuomat edut.

Microcracks and Vortices in Superconducting Thin Films

In this work, superconducting YBa₂ Cu₃O_6+x (YBCO) thin films have been studied with the experimental focus on the anisotropy of BaZrO₃ (BZO) doped YBCOthin films and the theoretical focus on modelling flux pinning by numerically solving Ginzburg- Landau equations. Also, the structural properties of undoped YBCO thin films grown on NdGaO₃ (NGO) and MgO substrates were investigated. The thin film samples were made by pulsed laser ablation on single crystal substrates. The structural properties of the thin films were characterized by X-ray diffraction and atomic force microscope measurements. The superconducting properties were investigated with a magnetometer and also with transport measurements in pulsed magnetic field up to 30 T. Flux pinning was modelled by restricting the value of the order parameter inside the columnar pinning sites and then solving the Ginzburg-Landau equations numerically with the restrictions in place. The computations were done with a parallel code on a supercomputer. The YBCO thin films were seen to develop microcracks when grown on NGO or MgO substrates. The microcrack formation was connected to the structure of the YBCO thin films in both cases. Additionally, the microcracks can be avoided by careful optimization of the deposition parameters and the film thickness. The BZO doping of the YBCO thin films was seen to decrease the effective electron mass anisotropy, which was seen by fitting the Blatter scaling to the angle dependence of the upper critical field. The Ginzburg-Landau simulations were able to reproduce the measured magnetic field dependence of the critical current density for BZO doped and undoped YBCO. The simulations showed that in addition to the large density also the large size of the BZO nanorods is a key factor behind the change in the power law behaviour between BZO doped and undoped YBCO. Additionally, the Ginzburg-Landau equations were solved for type I thin films where giant vortices were seen to appear depending on the film thickness. The simulations predicted that singly quantized vortices are stable in type I films up to quite large thicknesses and that the size of the vortices increases with decreasing film thickness, in a way that is similar to the behaviour of the interaction length of Pearl vortices.

Tasaisemmin jakaantuneen CIELAB-tyyppisen väriavaruuden määrittäminen värieroellipsien pääakselien eroja minimoimalla

Tässä työssä johdetaan lineaarimuunnoksella CIE x y z-värinsovitusfunktioista uudet värinsovitusfunktiot. Tarvittava muunnosmatriisi etsitään optimoimalla CIE ja BFD-RIT värieroellipsejä Matlab-ympäristössä. Työn tuloksena saatiin muunnosmatriisi, ja sillä muunnetut uudet värinsovitusfunktiot ja CIELAB-tyyppinen väriavaruus. Euklidisella etäisyydellä mitattuna CIE ja BFD-RIT värieroellipsien muoto ja koko paranivat noin kolmanneksen, mikä oli myös tavoitteena.

Epäsuoran kysyntätiedon hyödyntäminen verkkokaupan tuotevalikoima- ja hinnoittelupäätöksissä

Tässä diplomityössä tutkitaan, miten verkkokaupan kävijävirran käyttäytymistä analysoimalla voidaan tehdä perusteltuja, tarkoituksenmukaisiin nimikkeisiin ja niiden parametreihin kohdistuvia päätöksiä tilanteessa, jossa laajamittaisemmat historiatiedot toteutuneesta myynnistä puuttuvat. Teoriakatsauksen perusteella muodostettiin ratkaisumalli, joka perustuu potentiaalisten kysyntäajurien muodostamiseen ja testaamiseen. Testisarjan perusteella valittavaa ajuria käytetään estimoimaan nimikkeiden kysyntää, jolloin sitä voidaan käyttää toteutuneen myynnin sijasta esimerkiksi Pareto-analyysissä. Näin huomio on mahdollista keskittää rajattuun määrään merkitykseltään suuria nimikkeitä ja niiden yksityiskohtaisiin parametreihin, joilla on merkitystä asiakkaan ostopäätöstilanteissa. Lisäksi voidaan tunnistaa nimikkeitä, joiden ongelmana on joko huono verkkonäkyvyys tai yhteensopimattomuus asiakastarpeiden kanssa. Ajurien testaamisperiaatteena käytetään kertymäfunktioiden yhdenmukaisuustarkastelua, joka rakentuu kolmesta peräkkäisestä vaiheesta; visuaalisesta tarkastelusta, kahden otoksen 2-suuntaisesta Kolmogorov-Smirnov-yhteensopivuustestistä ja Pearsonin korrelaatiotestistä. Mallia ja sen avulla tuotettua kysynnän ajuria testattiin veneilyalan kuluttaja-asiakkaille suunnatussa verkkokaupassa, jossa sillä tunnistettiin Pareto-jakauman alkupäästä runsaasti nimikkeitä, joiden parametreissa oli myynnin kannalta epäedullisia tekijöitä. Jakauman toisessa päässä tunnistettiin satoja nimikkeitä, joiden ongelmana on ilmeisesti joko huono verkkonäkyvyys tai nimikkeiden yhteensopimattomuus asiakastarpeiden kanssa.

Keskitehoestimaattorin lisääminen diesel-sähköiseen hybridijärjestelmään

Nykyajan jatkuvasti kiristyvät päästörajoitukset ja ilmastonmuutoksen uhka ovat ajavia voimia kehittämään voimalaitosten tekniikkaa energiatehokkaampaan ja ympäristöystävällisempään suuntaan. Polttomoottoritekniikan parantaminen on tärkeä osa tätä kehitystä, mutta jo nykyisiä moottoreita voitaisiin ajaa energiate-hokkaammin käyttämällä akustoa ja älykästä säätöjärjestelmää apuna. Työssä tutkitaan simulaatioiden avulla voidaanko ulkomerellä toimivan huolto-aluksen energiatehokkuutta parantaa muokkaamalla sen tehon tuottoa keskitehoes-timaattorin ja akuston avulla.

Customer involvement in lean startup principles: case of game development studio

The objective of this thesis is to better understand customer’s role in lean startup methodology. The aim is to find out how customers are involved in lean startup methodology implantation and increase the likelihood of new venture survival. This study emphasizes the usage of customers in shaping of new product development processes within companies, through iteration and constant communication. This communication facilitates the development of features that are requested by the customers and enhances the prospects of the new venture. The empirical part of the study is a single qualitative case study that uses action research to implement the lean startup methodology into a pre-revenue venture and examines its customer involvement processes. The studied case company is Karaoke d.o.o., developing a game called kParty. The study used the theory discussed in the literature review: customer involvement (in the survey and interviews conducted for the lean startup methodology), lean principles (through the implementation of lean startup methodology) and lean startup methodology, which are the central building parts of this thesis as a whole. The thesis contributes to the understanding of customer involvement in lean startup methodology, while giving practical implications of customer orientation and product market fitting.