LWC-paperin opasiteetin parantaminen

LWC-syväpainopaperilta vaaditaan hyvän ajettavuuden, kiillon ja sileyden ohella hyvää opasiteettia. Tämä on asettanut haasteita LWC-paperin valmistajille paperin neliömassojen laskiessa. Tässä diplomityössä etsittiin keinoja parantaa kevyiden LWC-syväpainolajien opasiteettia heikentämättä oleellisesti muita tärkeitä paperin ominaisuuksia. Tavoitteena oli nostaa CR48-lajin opasiteetti tavoitearvoon 90 %. Työn kirjallisuusosassa perehdyttiin paperin optisten ominaisuuksien teoriaan sekä raaka-aineisiin ja prosessin osiin, joilla on vaikutusta paperin opasiteettiin. Työn kokeellisessa osassa tutkittiin olemassa olevan aineiston perusteella tekijöitä, joilla uskottiin olevan vaikutusta CR48-lajin opasiteettiin. Tutkimuksen ja kirjallisuuden perusteella ajettiin tehdaskoeajoa, joiden avulla pyrittiin parantamaan paperin opasiteettia. CR48-lajin opasiteettitavoite saavutettiin kolmella eri tavalla. Opasiteettitavoite saavutettiin, kun paperin vaaleus säädettiin tavoitearvoon pigmenttivärin avulla tumman hierteen sijasta. Tällöin väripigmentin määrää päällystyspastassa nostettiin 0,01 osaa ja valkaistun hierteen osuus kokonaishierteen määrästä oli 100 %. Vaaleuden säätö pastavärillä oli käytännössä hidasta ja hankalaa. Opasiteettitavoite saavutettiin myös, kun hierre jauhettiin täysin koeterillä. Koeterillä tapahtuva jauhatus oli rajumpaa ja katkovampaa kuin perinteisillä terillä, joten hienoaineen lisääntyminen ja kuidun lyheneminen paransivat paperin opasiteettia, mutta lujuudet huononivat. Lisäksi tavoiteopasiteetti saavutettiin, kun sellun osuutta vähennettiin 8 %-yksikköä. Lujuuden säilymisen kannalta sellun vähennys oli parempi keino opasiteetin parantamiseksi kuin hierteen jauhaminen koeterillä. Koeajojen perusteella pohjapaperin tuhkapitoisuuden nostolla ja hierteen CSF-luvun alentamisella ei ollut vaikutusta paperin opasiteettiin. Lisäksi 100 %:nen koeterillä jauhettu sahahakehierre antoi paperille huonomman opasiteetin kuin hierre, josta puolet oli jauhettu koeterillä ja raaka-aineesta 25 % oli sahahaketta.

Studies of Eu- and Yb-induced Reconstructions on the Si(100) Surface

This thesis presents experimental studies of rare earth (RE) metal induced structures on Si(100) surfaces. Two divalent RE metal adsorbates, Eu and Yb, are investigated on nominally flat Si(100) and on vicinal, stepped Si(100) substrates. Several experimental methods have been applied, including scanning tunneling microscopy/spectroscopy (STM/STS), low energy electron diffraction (LEED), synchrotron radiation photoelectron spectroscopy (SR-PES), Auger electron spectroscopy (AES), thermal desorption spectroscopy (TDS), and work function change measurements (Δφ). Two stages can be distinguished in the initial growth of the RE/Si interface: the formation of a two-dimensional (2D) adsorbed layer at submonolayer coverage and the growth of a three-dimensional (3D) silicide phase at higher coverage. The 2D phase is studied for both adsorbates in order to discover whether they produce common reconstructions or reconstructions common to the other RE metals. For studies of the 3D phase Yb is chosen due to its ability to crystallize in a hexagonal AlB2 type lattice, which is the structure of RE silicide nanowires, therefore allowing for the possibility of the growth of one-dimensional (1D) wires. It is found that despite their similar electronic configuration, Eu and Yb do not form similar 2D reconstructions on Si(100). Instead, a wealth of 2D structures is observed and atomic models are proposed for the 2×3-type reconstructions. In addition, adsorbate induced modifications on surface morphology and orientational symmetry are observed. The formation of the Yb silicide phase follows the Stranski-Krastanov growth mode. Nanowires with the hexagonal lattice are observed on the flat Si(100) substrate, and moreover, an unexpectedly large variety of growth directions are revealed. On the vicinal substrate the growth of the silicide phase as 3D islands and wires depends drastically on the growth conditions. The conditions under which wires with high aspect ratio and single orientation parallel to the step edges can be formed are demonstrated.

Sonata no. 2 in A major for violin and piano, op. 100 ("Thun")

Soitinnus: Viulu, piano.

Reaction Kinetics and Viscosity Modelling in the Fusion Syntheses of Ca- and Ca/Mg-resinates

Rosin is a natural product from pine forests and it is used as a raw material in resinate syntheses. Resinates are polyvalent metal salts of rosin acids and especially Ca- and Ca/Mg- resinates find wide application in the printing ink industry. In this thesis, analytical methods were applied to increase general knowledge of resinate chemistry and the reaction kinetics was studied in order to model the non linear solution viscosity increase during resinate syntheses by the fusion method. Solution viscosity in toluene is an important quality factor for resinates to be used in printing inks. The concept of critical resinate concentration, c crit, was introduced to define an abrupt change in viscosity dependence on resinate concentration in the solution. The concept was then used to explain the non-inear solution viscosity increase during resinate syntheses. A semi empirical model with two estimated parameters was derived for the viscosity increase on the basis of apparent reaction kinetics. The model was used to control the viscosity and to predict the total reaction time of the resinate process. The kinetic data from the complex reaction media was obtained by acid value titration and by FTIR spectroscopic analyses using a conventional calibration method to measure the resinate concentration and the concentration of free rosin acids. A multivariate calibration method was successfully applied to make partial least square (PLS) models for monitoring acid value and solution viscosity in both mid-infrared (MIR) and near infrared (NIR) regions during the syntheses. The calibration models can be used for on line resinate process monitoring. In kinetic studies, two main reaction steps were observed during the syntheses. First a fast irreversible resination reaction occurs at 235 °C and then a slow thermal decarboxylation of rosin acids starts to take place at 265 °C. Rosin oil is formed during the decarboxylation reaction step causing significant mass loss as the rosin oil evaporates from the system while the viscosity increases to the target level. The mass balance of the syntheses was determined based on the resinate concentration increase during the decarboxylation reaction step. A mechanistic study of the decarboxylation reaction was based on the observation that resinate molecules are partly solvated by rosin acids during the syntheses. Different decarboxylation mechanisms were proposed for the free and solvating rosin acids. The deduced kinetic model supported the analytical data of the syntheses in a wide resinate concentration region, over a wide range of viscosity values and at different reaction temperatures. In addition, the application of the kinetic model to the modified resinate syntheses gave a good fit. A novel synthesis method with the addition of decarboxylated rosin (i.e. rosin oil) to the reaction mixture was introduced. The conversion of rosin acid to resinate was increased to the level necessary to obtain the target viscosity for the product at 235 °C. Due to a lower reaction temperature than in traditional fusion synthesis at 265 °C, thermal decarboxylation is avoided. As a consequence, the mass yield of the resinate syntheses can be increased from ca. 70% to almost 100% by recycling the added rosin oil.

High pressure compression of filter cakes

The purpose of this thesis was to investigate the compression of filter cakes at high filtration pressures with five different test materials and to compare the energy consumption of high pressure compression with the energy consumption of thermal drying. The secondary target of this study was to investigate the particle deformation of test materials during filtration and compression. Literature part consists of basic theory of filtration and compression and of the basic parameters that influence the filtration process. There is also a brief description about all of the test materials including their properties and their industrial production and processing. Theoretical equations for calculating the energy consumptions of the filtrations at different conditions are also presented. At the beginning of the experiments at experimental part, the basic filtration tests were done with all the five test materials. Filtration tests were made at eight different pressures, from 6 bars up to 100 bars, by using piston press pressure filter. Filtration tests were then repeated by using a cylinder with smaller slurry volume than in the first series of filtration tests. Separate filtration tests were also done for investigating the deformation of solid particles during filtration and for finding the optimal curve for raising the filtration pressure. Energy consumption differences between high pressure filtration and ideal thermal drying process were done partly experimentally and partly by using theoretical calculation equations. By comparing these two water removal methods, the optimal ranges for their use were found considering their energy efficiency. The results of the measurements shows that the filtration rate increased and the moisture content of the filter cakes decreased as the filtration pressure was increased. Also the porosity of the filter cakes mainly decreased when the filtration pressure was increased. Particle deformation during the filtration was observed only with coal particles.

The Impact of Aspen and Alder on the Quality of NHBK

The purpose of this work was to study the effect of aspen and alder on birch cooking and the quality of the pulp produced. Three different birch kraft pulps were studied. As a reference, pure aspen and alder were included. The laboratory trials were done at the UPM Research Centre in Lappeenranta, Finland. The materials used were birch, aspen and alder mill chips that were collected around the area of South-Carelia in Finland. The chips used in the study were pulped using a standard kraft process. The pulps including birch fibres were ECF-bleached at laboratory scale to a target brightness of 85 %. The bleached pulps were beaten at low consistency by a laboratory Voith Sulzer refiner and tested for optical and physical properties. The theoretical part is a study of hardwoods that takes into accounts the differences between birch, aspen and alder. Major sub-areas were fibre and paper-technical properties as well as chemical composition and their influence on the different properties. The pulp properties of birch, aspen and alder found in previous studies were reported. Russian hardwood forest resources were also investigated. The fundamentals of kraft pulping and bleaching were studied at the end of theoretical part. The major effect of replacing birch with aspen and alder was the deterioration (lowering) of tensile and tear strengths. In other words, addition of aspen and alder to a birch furnish reduced strength properties. The reinforcement ability of the tested pulps was the following: 100 % birch > 80 % birch, 20 % aspen > 70 % birch, 20 % aspen, 10 % alder. The second thing noted was that blending of birch together with aspen and alder give better smoothness, optical properties and also formation. It can be concluded, that replacement of birch with alder during cooking by more than 10 % can negatively affect on the paper-technical properties of birch pulp. Mixing pure birch and aspen pulps would be more beneficial when producing printing paper made from chemical pulp.

Wet oxidation of recalcitrant lignin waters: Experimental and kinetic studies

The dissertation is based on four articles dealing with recalcitrant lignin water purification. Lignin, a complicated substance and recalcitrant to most treatment technologies, inhibits seriously pulp and paper industry waste management. Therefore, lignin is studied, using WO as a process method for its degradation. A special attention is paid to the improvement in biodegradability and the reduction of lignin content, since they have special importance for any following biological treatment. In most cases wet oxidation is not used as a complete ' mineralization method but as a pre treatment in order to eliminate toxic components and to reduce the high level of organics produced. The combination of wet oxidation with a biological treatment can be a good option due to its effectiveness and its relatively low technology cost. The literature part gives an overview of Advanced Oxidation Processes (AOPs). A hot oxidation process, wet oxidation (WO), is investigated in detail and is the AOP process used in the research. The background and main principles of wet oxidation, its industrial applications, the combination of wet oxidation with other water treatment technologies, principal reactions in WO, and key aspects of modelling and reaction kinetics are presented. There is also given a wood composition and lignin characterization (chemical composition, structure and origin), lignin containing waters, lignin degradation and reuse possibilities, and purification practices for lignin containing waters. The aim of the research was to investigate the effect of the operating conditions of WO, such as temperature, partial pressure of oxygen, pH and initial concentration of wastewater, on the efficiency, and to enhance the process and estimate optimal conditions for WO of recalcitrant lignin waters. Two different waters are studied (a lignin water model solution and debarking water from paper industry) to give as appropriate conditions as possible. Due to the great importance of re using and minimizing the residues of industries, further research is carried out using residual ash of an Estonian power plant as a catalyst in wet oxidation of lignin-containing water. Developing a kinetic model that includes in the prediction such parameters as TOC gives the opportunity to estimate the amount of emerging inorganic substances (degradation rate of waste) and not only the decrease of COD and BOD. The degradation target compound, lignin is included into the model through its COD value (CODligning). Such a kinetic model can be valuable in developing WO treatment processes for lignin containing waters, or other wastewaters containing one or more target compounds. In the first article, wet oxidation of "pure" lignin water was investigated as a model case with the aim of degrading lignin and enhancing water biodegradability. The experiments were performed at various temperatures (110 -190°C), partial oxygen pressures (0.5 -1.5 MPa) and pH (5, 9 and 12). The experiments showed that increasing the temperature notably improved the processes efficiency. 75% lignin reduction was detected at the lowest temperature tested and lignin removal improved to 100% at 190°C. The effect of temperature on the COD removal rate was lower, but clearly detectable. 53% of organics were oxidized at 190°C. The effect of pH occurred mostly on lignin removal. Increasing the pH enhanced the lignin removal efficiency from 60% to nearly 100%. A good biodegradability ratio (over 0.5) was generally achieved. The aim of the second article was to develop a mathematical model for "pure" lignin wet oxidation using lumped characteristics of water (COD, BOD, TOC) and lignin concentration. The model agreed well with the experimental data (R2 = 0.93 at pH 5 and 12) and concentration changes during wet oxidation followed adequately the experimental results. The model also showed correctly the trend of biodegradability (BOD/COD) changes. In the third article, the purpose of the research was to estimate optimal conditions for wet oxidation (WO) of debarking water from the paper industry. The WO experiments were' performed at various temperatures, partial oxygen pressures and pH. The experiments showed that lignin degradation and organics removal are affected remarkably by temperature and pH. 78-97% lignin reduction was detected at different WO conditions. Initial pH 12 caused faster removal of tannins/lignin content; but initial pH 5 was more effective for removal of total organics, represented by COD and TOC. Most of the decrease in organic substances concentrations occurred in the first 60 minutes. The aim of the fourth article was to compare the behaviour of two reaction kinetic models, based on experiments of wet oxidation of industrial debarking water under different conditions. The simpler model took into account only the changes in COD, BOD and TOC; the advanced model was similar to the model used in the second article. Comparing the results of the models, the second model was found to be more suitable for describing the kinetics of wet oxidation of debarking water. The significance of the reactions involved was compared on the basis of the model: for instance, lignin degraded first to other chemically oxidizable compounds rather than directly to biodegradable products. Catalytic wet oxidation of lignin containing waters is briefly presented at the end of the dissertation. Two completely different catalysts were used: a commercial Pt catalyst and waste power plant ash. CWO showed good performance using 1 g/L of residual ash gave lignin removal of 86% and COD removal of 39% at 150°C (a lower temperature and pressure than with WO). It was noted that the ash catalyst caused a remarkable removal rate for lignin degradation already during the pre heating for `zero' time, 58% of lignin was degraded. In general, wet oxidation is not recommended for use as a complete mineralization method, but as a pre treatment phase to eliminate toxic or difficultly biodegradable components and to reduce the high level of organics. Biological treatment is an appropriate post treatment method since easily biodegradable organic matter remains after the WO process. The combination of wet oxidation with subsequent biological treatment can be an effective option for the treatment of lignin containing waters.

Physical Realization of an Optical Automatic Target Recognition System

In the modern warfare there is an active development of a new trend connected with a robotic warfare. One of the critical elements of robotics warfare systems is an automatic target recognition system, allowing to recognize objects, based on the data received from sensors. This work considers aspects of optical realization of such a system by means of NIR target scanning at fixed wavelengths. An algorithm was designed, an experimental setup was built and samples of various modern gear and apparel materials were tested. For pattern testing the samples of actively arm engaged armies camouflages were chosen. Tests were performed both in clear atmosphere and in the artificial extremely humid and hot atmosphere to simulate field conditions.

Source and Target Text-Orientation in Drama Translation. An Analysis of Four Translations of William Shakespeare’s Julius Caesar

Tässä pro gradu -tutkielmassa käsittelen lähde- ja kohdetekstikeskeisyyttä näytelmäkääntämisessä. Tutkimuskohteina olivat käännösten sanasto, syntaksi, näyttämötekniikka, kielikuvat, sanaleikit, runomitta ja tyyli. Tutkimuksen tarkoituksena oli selvittää, näkyykö teoreettinen painopisteen siirtyminen lähdetekstikeskeisyydestä kohdetekstikeskeisyyteen suomenkielisessä näytelmäkääntämisessä. Oletuksena oli, että siirtyminen näkyy käytetyissä käännösstrategioissa. Tutkimuksen teoriaosuudessa käsitellään ensin lähde- ja kohdetekstikeskeisiä käännösteorioita. Ensin esitellään kaksi lähdetekstikeskeistä teoriaa, jotka ovat Catfordin (1965) muodollinen vastaavuus ja Nidan (1964) dynaaminen ekvivalenssi. Kohdetekstikeskeisistä teorioista käsitellään Touryn (1980) ja Newmarkin (1981) teoreettisia näkemyksiä sekä Reiss ja Vermeerin (1986) esittelemää skopos-teoriaa. Vieraannuttamisen ja kotouttamisen periaatteet esitellään lyhyesti. Teoriaosuudessa käsitellään myös näytelmäkääntämistä, William Shakespearen kieltä ja siihen liittyviä käännösongelmia. Lisäksi esittelen lyhyesti Shakespearen kääntämistä Suomessa ja Julius Caesarin neljä kääntäjää. Tutkimuksen materiaalina oli neljä Shakespearen Julius Caesar –näytelmän suomennosta, joista Paavo Cajanderin käännös on julkaistu vuonna 1883, Eeva-Liisa Mannerin vuonna 1983, Lauri Siparin vuonna 2006 ja Jarkko Laineen vuonna 2007. Analyysissa käännöksiä verrattiin lähdetekstiin ja toisiinsa ja vertailtiin kääntäjien tekemiä käännösratkaisuja. Tulokset olivat oletuksen mukaisia. Lähdetekstikeskeisiä käännösstrategioita oli käytetty uusissa käännöksissä vähemmän kuin vanhemmissa. Kohdetekstikeskeiset strategiat erosivat huomattavasti toisistaan ja uusinta käännöstä voi sanoa adaptaatioksi. Jatkotutkimuksissa tulisi materiaali laajentaa koskemaan muitakin Shakespearen näytelmien suomennoksia. Eri aikakausien käännöksiä tulisi verrata keskenään ja toisiinsa, jotta voitaisiin luotettavasti kuvata muutosta lähde- ja kohdetekstikeskeisten käännösstrategioiden käytössä ja eri aikakausien tyypillisten strategioiden kartoittamiseksi.

Considering Target Groups in the Creation of a Comprehensive City Branding Process

The aim of the research was to create a comprehensive city branding process. This was done by identifying the key target groups of the city and considering them in the city branding process. Also key stakeholders were identified and taken into consideration when creating the branding process. As an empirical study, three first stages of the city branding process were implemented for the city of Lappeenranta having "students" as the case target group. An interview with the city officials was conducted, as well as a student survey on the current city image of Lappeenranta. Quantitative research methods were used to analyze the results of the survey. A comprehensive city branding process with eight stages was created in the research. Target groups were considered in the process by identifying the target group dependent stages. The empirical study revealed that the current city image held by the students consists of six dimensions. These dimensions were analyzed from the viewpoint of Lappeenranta with the help of an importance performance analysis.