Jauhinterien valmistuksen kehittäminen

Diplomityö käsittelee eräälle paperiteollisuuden komponentteja valmistavalle yritykselle tehtyä tutkimusta, jossa tutkittiin erilaisia valmistusmenetelmiä, joilla voidaan valmistaa uudenlaisia jauhinteriä. Diplomityössä ideoitiin erilaisia jauhinteränkonstruktiovaihtoehtoja. Vaihtoehtoja havainnollistamaan piirrettiin jokaisesta ratkaisusta 3D- mallit. Vaihtoehtojen pohjalta päätettiin suoritettavat valmistustestaukset. Työssä suoritettiin valmistustestejä kuitulaserilla, hiilidioksidilaserilla sekä hienosädeplasmalla. Näiden testien perusteella saatiin näkemys siitä, mikä konstruktiovaihto on valmistusteknisesti paras, täyttäen samalla jauhinterälle asetetut vaatimukset. Diplomityön tuloksena syntyi toimiva ja kustannustehokas ratkaisu jauhinterien valmistamiseksi.

Mittausjärjestelmän kehittäminen massansyöttöön

Tämän diplomityön tavoitteena on kehittää menetelmä mitata keskisakeuksisen sellumassan virtausta; suuntaa ja suuruutta, vapaassa tilassa ja kehittää koelaite, jolla sellupesurin massansyöttötapahtumaa voidaan tutkia sekä rakenteellisesta että prosessinäkökulmasta. Virtausmittausmenetelmän kehityksessä arvioitiin ensin erilaisten perusmittausmenetelmien soveltuvuutta keskisakeuksisen sellumassan virtausmittaukseen. Valitun menetelmän, vastusvenymäliuskamittauksen, kehityksessä ideoitiin sekä anturin mittoja ja geometriaa että virtauskappaleiden geometriaa. Lopullisella anturikonstruktiolla suoritettiin virtausmittauskokeita erilaisilla virtauskappaleilla putkivirtauksessa. Virtausaineena oli vesi sekä sellumassa eri sakeuksissa. Tulosten analysoinnin perusteella suoritettiin valitulla virtauskappaleella alustava koeajo prosessilaitteessa. Koelaitteen kehityksessä määritettiin ensin laitteelle tutkimukselliset tavoitteet. Erilaisia tutkimusmenetelmien arvioinnin perustella valittiin koelaitteeseen sopivat menetelmät. Tutkimuksellisten tavoitteiden ja sovellettavien menetelmien perusteella mitoitettiin ja suunniteltiin koelaite.

The Strengths and Difficulties Questionnaire (SDQ-Fin) among Finnish children and adolescents

Objective: The psychometric properties of The Strengths and Difficulties Questionnaire (SDQ-Fin), a Finnish version of a brief screening instrument were studied. Emotional and behavioural problems of 7- to 15-year-olds measured by the SDQ were reported, as well as the occurrence of self-reported eating disturbance symptoms and alcohol use among adolescents. Methods and samples: The cross-sectional school survey included 25 items of the SDQ-Fin, items about eating disturbance, alchol use and child psychiatric help-seeking. The study consists of three community samples: 1. The SDQ-Fin parent (n = 703) and teacher (n = 376) versions of 7 – 12 –year-olds, and self-report versions (n = 528) of 11 – 16 years-olds were obtained, and 2. the parent (n = 81) and self-report versions of 15-16 –year olds (n = 129) were obtained in Laitila and Pyhäranta. 3. The self-report versions of 13 – 16 – year-olds (n = 1458) in Salo and Rovaniemi were obtained. Results: The psychometric properties of the SDQ-Fin were for the most part comparable with the other European SDQ research results. The internal consistency (Cronbach’s alpha = 0.71 in all informants’ reports) and inter-rater reliability (between the pairs of reports r = 0.38 - 0.44) were adequate. The concurrent validity (r = 0.75 between the SDQ and the CBCL total scores; r = 0.71 between the SDQ and the YSR total scores) was sufficient. Factor analysis of the SDQ self-report generally confirmed the postulated structure for girls and boys, except for the conduct problems scale of boys, which was fused with emotional symptoms and with hyperactivity. The response rates, means and cut-off points of the SDQ self-report scores were similar to those found, e.g. in Norway and in Britain. A high level of psychological problems, especially emotional and conduct problems and hyperactivity-inattention, were associated with high level of eating disturbance symptoms and alcohol use. Conclusion: The results showed that the psychometric properties of the SDQ-Fin are adequate and provide additional confirmation of the usefulness of the SDQ-Fin for, e.g. screening, epidemiological research and clinical purposes.

Flexible Multibody Simulation Approach in the Dynamic Analysis of Bone Strains Activity

The objective of this study is to show that bone strains due to dynamic mechanical loading during physical activity can be analysed using the flexible multibody simulation approach. Strains within the bone tissue play a major role in bone (re)modeling. Based on previous studies, it has been shown that dynamic loading seems to be more important for bone (re)modeling than static loading. The finite element method has been used previously to assess bone strains. However, the finite element method may be limited to static analysis of bone strains due to the expensive computation required for dynamic analysis, especially for a biomechanical system consisting of several bodies. Further, in vivo implementation of strain gauges on the surfaces of bone has been used previously in order to quantify the mechanical loading environment of the skeleton. However, in vivo strain measurement requires invasive methodology, which is challenging and limited to certain regions of superficial bones only, such as the anterior surface of the tibia. In this study, an alternative numerical approach to analyzing in vivo strains, based on the flexible multibody simulation approach, is proposed. In order to investigate the reliability of the proposed approach, three 3-dimensional musculoskeletal models where the right tibia is assumed to be flexible, are used as demonstration examples. The models are employed in a forward dynamics simulation in order to predict the tibial strains during walking on a level exercise. The flexible tibial model is developed using the actual geometry of the subject’s tibia, which is obtained from 3 dimensional reconstruction of Magnetic Resonance Images. Inverse dynamics simulation based on motion capture data obtained from walking at a constant velocity is used to calculate the desired contraction trajectory for each muscle. In the forward dynamics simulation, a proportional derivative servo controller is used to calculate each muscle force required to reproduce the motion, based on the desired muscle contraction trajectory obtained from the inverse dynamics simulation. Experimental measurements are used to verify the models and check the accuracy of the models in replicating the realistic mechanical loading environment measured from the walking test. The predicted strain results by the models show consistency with literature-based in vivo strain measurements. In conclusion, the non-invasive flexible multibody simulation approach may be used as a surrogate for experimental bone strain measurement, and thus be of use in detailed strain estimation of bones in different applications. Consequently, the information obtained from the present approach might be useful in clinical applications, including optimizing implant design and devising exercises to prevent bone fragility, accelerate fracture healing and reduce osteoporotic bone loss.

A Practical Micro Mechanical Model Based Local Approach Methodology for the Analysis of Ductile Fracture of Welded T-Joints

This thesis concentrates on developing a practical local approach methodology based on micro mechanical models for the analysis of ductile fracture of welded joints. Two major problems involved in the local approach, namely the dilational constitutive relation reflecting the softening behaviour of material, and the failure criterion associated with the constitutive equation, have been studied in detail. Firstly, considerable efforts were made on the numerical integration and computer implementation for the non trivial dilational Gurson Tvergaard model. Considering the weaknesses of the widely used Euler forward integration algorithms, a family of generalized mid point algorithms is proposed for the Gurson Tvergaard model. Correspondingly, based on the decomposition of stresses into hydrostatic and deviatoric parts, an explicit seven parameter expression for the consistent tangent moduli of the algorithms is presented. This explicit formula avoids any matrix inversion during numerical iteration and thus greatly facilitates the computer implementation of the algorithms and increase the efficiency of the code. The accuracy of the proposed algorithms and other conventional algorithms has been assessed in a systematic manner in order to highlight the best algorithm for this study. The accurate and efficient performance of present finite element implementation of the proposed algorithms has been demonstrated by various numerical examples. It has been found that the true mid point algorithm (a = 0.5) is the most accurate one when the deviatoric strain increment is radial to the yield surface and it is very important to use the consistent tangent moduli in the Newton iteration procedure. Secondly, an assessment of the consistency of current local failure criteria for ductile fracture, the critical void growth criterion, the constant critical void volume fraction criterion and Thomason's plastic limit load failure criterion, has been made. Significant differences in the predictions of ductility by the three criteria were found. By assuming the void grows spherically and using the void volume fraction from the Gurson Tvergaard model to calculate the current void matrix geometry, Thomason's failure criterion has been modified and a new failure criterion for the Gurson Tvergaard model is presented. Comparison with Koplik and Needleman's finite element results shows that the new failure criterion is fairly accurate indeed. A novel feature of the new failure criterion is that a mechanism for void coalescence is incorporated into the constitutive model. Hence the material failure is a natural result of the development of macroscopic plastic flow and the microscopic internal necking mechanism. By the new failure criterion, the critical void volume fraction is not a material constant and the initial void volume fraction and/or void nucleation parameters essentially control the material failure. This feature is very desirable and makes the numerical calibration of void nucleation parameters(s) possible and physically sound. Thirdly, a local approach methodology based on the above two major contributions has been built up in ABAQUS via the user material subroutine UMAT and applied to welded T joints. By using the void nucleation parameters calibrated from simple smooth and notched specimens, it was found that the fracture behaviour of the welded T joints can be well predicted using present methodology. This application has shown how the damage parameters of both base material and heat affected zone (HAZ) material can be obtained in a step by step manner and how useful and capable the local approach methodology is in the analysis of fracture behaviour and crack development as well as structural integrity assessment of practical problems where non homogeneous materials are involved. Finally, a procedure for the possible engineering application of the present methodology is suggested and discussed.

Water circulations for effective bleaching of high-brightness mechanical pulps

The amount of water available is usually restricted, which leads to a situation where a complete understanding of the process, including water circulations and the influence of water components, is essential. The main aim of this thesis was to clarify the possibilities for the efficient use of residual peroxide by means of water circulation rearrangements. Rearranging water circulations and the reduction of water usage may cause new problems, such as metal induced peroxide decomposition that needs to be addressed. This thesis introduces theoretical methods of water circulations to combine two variables; effective utilization of residual peroxide and avoiding manganese in the alkaline peroxide bleaching stage. Results are mainly based on laboratory and mill site experiments concerning the utilization of residual peroxide. A simulation model (BALAS) was used to evaluate the manganese contents and residual peroxide doses. It was shown that with optimum recirculation of residual peroxide the brightness can be improved or chemical costs can be decreased. From the scientific perspective, it was also very important to discover that recycled peroxide was more effective pre-bleaching agent compared to fresh peroxide. This can be due to the organic acids i.e. per acetic acid in wash press filtrate that have been formed in alkaline bleaching stage. Even short retention time was adequate and the activation of residual peroxide using sodium hydroxide was not necessary. There are several possibilities for using residual peroxide in practice regarding bleaching. A typical modern mechanical pulping process line consist of defibering, screening, a disc filter, a bleach press, high consistency (HC) peroxide bleaching and a wash press. Furthermore there usually is not a particular medium consistency (MC) pre-bleaching stage that includes additional thickening equipment. The most advisable way to utilize residual peroxide in this kind of process is to recycle the wash press filtrate to the dilution of disc filter pulp (low MC pre-bleaching stage). An arrangement such as this would be beneficial in terms of the reduced convection of manganese to the alkaline bleaching stage. Manganese originates from wood material and will be removed to the water phase already in the early stages of the process. Recycling residual peroxide prior to the disc filter is not recommended because of low consistencies. Regarding water circulations, the novel point of view is that, it would be beneficial to divide water circulations into two sections and the critical location for the division is the disc filter. Both of these two sections have their own priority. Section one before the disc filter: manganese removal. Section two after the disc filter: brightening of pulp. This division can be carried out if the disc filter pulp is diluted only by wash press filtrate before the MC storage tower. The situation is even better if there is an additional press after the disc filter, which will improve the consistency of the pulp. This has a significant effect on the peroxide concentration in the MC pre-bleaching stage. In terms of manganese content, it is essential to avoid the use of disc filter filtrate in the bleach press and wash press showers. An additional cut-off press would also be beneficial for manganese removal. As a combination of higher initial brightness and lower manganese content, the typical brightness increase varies between approximately 0.5 and 1% ISO units after the alkaline peroxide bleaching stage. This improvement does not seem to be remarkable, but as it is generally known, the final brightness unit is the most expensive and difficult to achieve. The estimation of cost savings is not unambiguous. For example in GW/TMP mill case 0.6% ISO units higher final brightness gave 10% savings in the costs of bleaching chemicals. With an hypothetical 200 000 ton annual production, this means that the mill could save in the costs of bleaching chemicals more than 400 000 euros per year. In general, it can be said that there were no differences between the behavior of different types of processes (GW, PGW, TMP and BCTMP). The enhancement of recycling gave a similar response in all cases. However, we have to remember that the utilization of residual peroxide in older mills depends a great deal on the process equipment, the amount of water available and existing pipeline connections. In summary, it can be said that processes are individual and the same solutions cannot be applied to all cases.

Märkäosan lisäaineet ja kuituflokit konesihdin ympäristössä

Painelajittelu on yksi yleisimmistä yksikköprosesseista paperin ja sellun valmistuksessa. Suurelta osin lajittimet toimivat niille asetettujen vaatimusten mukaisesti, mutta joissakin tapauksissa lajittimissa saattaa esiintyä ei-toivottavaa kuitujen kasautumista sekä kehräymän muodostusta. Niiden seurauksena lajittimien kapasiteetti alenee ja lajittelutulos heikkenee. Tämän työn tarkoituksena on uutta kuvantamistekniikkaa hyödyntäen selvittää miten kehräymät ja kuitukasaumat syntyvät painelajittimen sihtipinnalla ja miten retentioaineen syöttö sihdin ympäristössä vaikuttaa niiden syntyyn. Työn kirjallisuusosassa tarkastellaan painelajittimen toimintaa, rakennetta sekä lyhyen kierron konesihdin erityispiirteitä. Lisäksi tarkastellaan retentiokemikaalien käyttäytymistä leikkausvoimien alaisuudessa ja kuitukehräymien syntyä painelajittimissa. Kokeellisessa osassa on raportoitu kuvantamisjärjestelmällä saatuja tuloksia sekä esitetään havaintoja kehräymien ja kuitukasaumien synnystä ja niiden vaikutuksista painelajittimen toimintaan. Kuvausten perusteella voidaan sanoa, että kehräymän syntyminen sihdissä vaatii aina jonkinlaisen kuitukasauman olemassaoloa. Tällaista alkukasaumaa tarvitaan, jotta kuidut voivat ankkuroitua siihen kiinni ja johon kiinnittyneenä kuidut alkavat pyöriä virtauksessa muodostaen kehräymää. Kuitukasauman muodostuminen painelajittimessa johtuu pääosin sihdissä olevasta epäjatkuvuuskohdasta, massassa olevista epäpuhtauksista ja kuituflokeista jotka jäävät kiinni sihtipinnan aukkoihin tai lajittimen kapasiteetin ylittymisestä. Kehräymän syntyä kasauman jäljessä voidaan pitää enemmän sääntönä kuin poikkeuksena, mutta kehräytyminen on vähäisempää reikäsihdillä kuin rakosihdillä. Silloituspolymeerillä flokattu massa ei muodosta herkemmin kuitukasaumia sihtipintaan verrattuna flokkaamattomaan massaan. Lajiteltavan massan sakeuden nosto vähentää kuitukasaumien ja kehräymien syntyä. Kuitukasaumien ja kehräymien välttämiseksi on tärkeää, että sihtiä ei ajeta suunniteltua mitoitusaluetta suuremmilla tuotannoilla tai virtauksilla.

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.

Social competence and loneliness during the school years - Issues in assessment, interrelations and intergenerational transmission

Väitöskirjassa tarkastellaan kouluikäisten lasten ja nuorten sosiaalisen kompetenssin ja yksinäisyyden mittaamista, yhteyksiä ja periytyvyyttä vanhemmilta heidän lapsilleen. Alakouluikäisten lasten tutkimusaineisto (n=985) koostuu lapsilta itseltään, heidän luokkatovereiltaan, opettajiltaan ja vanhemmiltaan vuosina 2000 - 2004 osana Merkitystä etsimässä – tutkimusprojektia (M. Vauras) kerätystä aineistosta. Mukana on itse-, toveri-, opettaja- ja vanhempien arviot lasten sosiaalisesta kompetenssista, seuranta-aineisto lasten yksinäisyydestä, opettajien arviot lasten motivationaalisesta orientaatiosta, standardoiduin testisarjoin arvioidut akateemiset taidot sekä lasten äitien ja isien arviot omasta yksinäisyydestään ja koetusta kyvykkyydestään toimia vanhempana. Yläkouluikäisten nuorten (n=386) aineisto koostuu vuosina 2006 – 2007 osana Sosioemotionaalinen oppiminen ja hyvinvointi yläkouluyhteisössä (P. M. Niemi) kerätystä nuorten yksinäisyyden, sosiaalisen ahdistuneisuuden ja sosiaalisen fobian seuranta-aineistosta. Mitattavuutta (päätavoite 1) tutkittiin erityisesti monitahoarviointien rakenteiden yhtenäisyyksiä, subjektiivisten arvioiden ajallista pysyvyyttä sekä mittareiden validiteettia ja reliabiliteettia testaamalla. Sosiaalisen kompetenssin ja yksinäisyyden keskinäisten yhteyksien lisäksi tarkasteltiin näiden yhteyttä alakoululaisten oppimiseen sekä yläkou¬lulaisten psykososiaaliseen hyvinvointiin (päätavoite 2). Kolmantena päätavoitteena oli selvittää yksinäisyyden mahdollista periytymistä vanhemmilta lapsille. Osana ensimmäistä päätavoitetta kehitettiin Monitahoarviointi sosiaalisesta kompetenssista (MASK) -arviointimenetelmä (artikkeli 1). Konfirmatorisen faktorianalyysin tulosten perusteella nelifaktorinen rakenne (prososiaalisuus sisältäen yhteistyötaidot ja empatiakyvyn sekä antisosiaalisuus sisältäen impulsiivisuuden ja häiritsevyyden) sopi sekä lasten itsensä, heidän luokkatovereidensa, opettajiensa että vanhempiensa tekemiin arviointeihin. Eri tahojen arviointien väliset korrelaatiot olivat tilastollisesti merkitseviä, joskin suhteellisen matalia, ts. eri tahojen näkökulmat lapsen sosiaalisesta kompetenssista ovat toisistaan eriäviä. Täten eri arvioitsijatahojen käyttäminen on kokonaisuuden tutkimisen kannalta tärkeää. Toisena mittaamiseen liittyvänä tavoitteena oli validoida Hozan, Bukowskin ja Beeryn (2000) sosiaalisen ja emotionaalisen yksinäisyyden mittari suomalaisille lapsille (artikkeli 3) ja nuorille (artikkeli 4) soveltuvaksi sekä tutkia, ovatko lasten ja nuorten arviot omasta yksinäisyydestään ajallisesti pysyviä. Alakoululaisten lasten osalta yksinäisyys, erityisesti sosiaalinen yksinäisyys osoittautui suhteellisen pysyväksi, mutta vahvistui entisestään yläkouluikäisten nuorten aineistoa tarkasteltaessa. Huomionarvoista sekä ala- että yläkoululaisten aineistoissa oli poikien kokema vahva emotionaalinen yksinäisyys. Molempien mittareiden osalta sekä validiteetti että reliabiliteetti todettiin hyväksyttäväksi ja niitä voidaan suositella lasten ja nuorten sosiaalisen kompetenssin ja yksinäisyyden arviointimenetelmiksi. Toisena päätavoitteena oli rakenneyhtälömallinnuksen keinoin tarkastella sosiaalisen kompetenssin ja yksinäisyyden yhteyksiä sekä keskenään (artikkelit 2 ja 3) että suhteessa lasten oppimiseen (artikkeli 2) ja nuorten psykososiaaliseen hyvinvointiin (artikkeli 4). Alakouluikäisten lasten osalta sosiaalinen kompetenssi oli yhteydessä pait¬si yksinäisyyteen myös opettajien oppilaistaan tekemiin motivationaalisen orientaation arvioihin sekä standardoiduin testien arvioituihin akateemisiin taitoihin. Yläkouluikäisten nuorten osalta yksinäisyys oli yhteydessä sosiaaliseen ahdistuneisuuteen ja sosiaaliseen fobiaan. Täten sosiaalisen kompetenssin voidaan katsoa olevan koululaisten hyvinvointia ja oppimista vahvistava, ja toisaalta yksinäisyyden nuorten psykososiaalista hyvinvointia heikentävä tekijä. Viimeisenä päätavoitteena mallinnettiin yksinäisyyden mahdollista periytyvyyttä. Ensimmäisessä vaiheessa periytyvyyttä tarkasteltiin koko perheen sisällä, vanhempien tai lasten sukupuolta erottelematta (artikkeli 2). Tässä rakenneyhtälömallissa vanhempien kokema yksinäisyys ennusti heikompaa kyvykkyydentunnetta vanhemmuudesta, joka edelleen ennusti lapsen heikompaa toveriarvioitua sosiaalista kompetenssia koulussa ja tätä kautta vahvempaa yksinäisyyden kokemusta. Toisessa mallissa eroteltiin äitien ja isien sekä tyttöjen ja poikien aineistot, jotta periytyvyyttä voitiin tarkastella äiti-tytär, äiti-poika, isä-tytär ja isä-poika dyadisuhteissa. Rakenneyhtälömallinnuksen tulosten perusteella sekä äitien että isien kokema yksinäisyys ennusti

Kuplakokojakauman hallinta happidelignifioinnissa

Työn tarkoituksena oli uutta kuvantamistekniikkaa hyödyntäen tutkia erilaisten tekijöiden vaikutusta kaasun dispergoitumiseen kemikaalisekoittimessa, kun kaasua sekoitetaan keskisakeaan massaan. Lisäksi työssä pyrittiin selvittämään, kuinka paljon kuitususpensioon tuotettu kaasufaasin kuplakokojakauma vaikuttaa happidelignifioinnin tulokseen. Kaasumaisten aineiden käyttäytymistä keskisakeissa kuitususpensiossa ei tarkkaan tunneta. Mikäli kaasumaisen hapen käyttäytymisestä saadaan uutta tietoa, tarjoaa tämä muun muassa uusia mahdollisuuksia kaasua sekoittavien laitteiden tuotekehityksessä. Työn kokeellinen osuus koostui kahdesta osasta, joista ensimmäisessä osassa selvitettiin sekoittimen roottorin pyörimisnopeuden, reaktorin kaasutilavuuden sekä suspension sakeuden vaikutusta muodostuvaan kaasun kuplakokojakaumaan. Työn jälkimmäisessä osassa arvioitiin yksivaiheisten keskisakeudessa tehtyjen happidelignifiointien perusteella suspensioon tuotetun kaasun kuplakokojakauman merkitystä happidelignifiointitulokseen. Kuplakokojakaumat määritettiin reaktoriin kiinnitetyllä kameralla kuvatuista valokuvista, joita otettiin sekoitustapahtuman aikana. Työn tuloksien perusteella sekoituksen voimakkuudella oli suurin vaikutus suspensioon muodostuvan kuplakokojakauman kannalta. Roottorin kierrosnopeuden kasvaessa kaasun keskimääräinen kuplakoko pieneni sekä havaittujen kuplien lukumäärää kasvoi huomattavasti. Myös suspension sakeuden kasvattamisen havaittiin vaikuttavan kuplakokoon pienentävästi. Happidelignifioinneissa saavutettiin paras kappareduktio, kun kaasun kuplakoko oli mahdollisimman pieni. Käytetty kuvantamistekniikka on tiettävästi ensimmäinen menetelmä, jolla saadaan reaaliaikaista tietoa vain muutamien kymmenien mikrometrien kokoisten kaasukuplien käyttäytymisestä oikeassa prosessitilanteessa.

Improving Quality of Life of Patients With Schizophrenia In Acute Psychiatric Wards

The overall goal of this study was to identify means by which the quality of life (QoL) of patients with schizophrenia could be improved in acute psychiatric wards. First, subjective QoL of patients (n=35) was explored. Second, two different QoL instruments (EuroQoL-5D, EQ-5D; Quality of Life Enjoyment and Satisfaction Questionnaire Short Form, Q-LES-Q SF) were examined. Third, patients’ (n=35) and nurses’ (n=29) perceptions of nursing interventions to support patients’ QoL were examined. Fourth, the effect of three different patient education methods on patients’ QoL (n=311) was compared. The data were collected during the period 2005-2007. Patients named health, family, leisure activities, work or study, and social relationships most frequently as their important QoL areas. It emerged that patients’ QoL was impaired. Examination of two QoL instruments showed that the EQ-5D has moderate and the Q-LES-Q SF good internal consistency. Moreover, both instruments proved to be reasonably valid and feasible for use with patients with schizophrenia. Altogether six nursing interventions which nurses use to support patients’ QoL, and which should be further developed were identified from nurses’ descriptions: interventions related to care planning, empowering interventions, social interventions, activating interventions, security interventions, and interventions to support physical health. Evaluation of different patient education methods showed that patients’ QoL improved significantly during follow-up. No significant differences between groups were found. In light of the findings it is recommended to assess QoL of patients with schizophrenia as a basis for care planning and care evaluation in clinical settings. Valid and feasible instruments should be used in this assessment. Moreover, it is recommend that nursing interventions should be further developed to better improve patients’ QoL.

Biochemical Modification of Thermomechanical Pulp Fibers

The first objective of this study was to find out reliable laboratory methods to predict the effect of enzymes on specific energy consumption and fiber properties of TMP pulp. The second one was to find with interactive software called “Knowledge discovery in databases” enzymes or other additives that can be used in finding a solution to reduce energy consumption of TMP pulp. The chemical composition of wood and enzymes, which have activity on main wood components were presented in the literature part of the work. The results of previous research in energy reduction of TMP process with enzymes were also highlighted. The main principles of knowledge discovery have been included in literature part too. The experimental part of the work contains the methods description in which the standard size chip, crushed chip and fiberized spruce chip (fiberized pulp) were used. Different types of enzymatic treatment with different dosages and time were tested during the experiments and showed. Pectinase, endoglucanase and mixture of enzymes were used for evaluation of method reliability. The fines content and fiber length of pulp was measured and used as evidence of enzymes' effect. The refining method with “Bauer” laboratory disc refiner was evaluated as not highly reliable. It was not able to provide high repeatability of results, because of uncontrolled feeding capacity and refining consistency. The refining method with Valley refiner did not have a lot of variables and showed stable and repeatable results in energy saving. The results of experiments showed that efficient enzymes impregnation is probably the main target with enzymes application for energy saving. During the work the fiberized pulp showed high accessibility to enzymatic treatment and liquid penetration without special impregnating equipment. The reason was that fiberized pulp has larger wood surface area and thereby the contact area between the enzymatic solution and wood is also larger. Standard size chip and crushed chip treatment without special impregnator of enzymatic solution was evaluated as not efficient and did not show visible, repeatable results in energy consumption decrease. Thereby it was concluded that using of fiberized pulp and Valley refiner for measurements of enzymes' effectiveness in SEC decrease is more suitable than normal size chip and crushed chip with “Bauer” refiner. Endoglucanase with 5 kg/t dosage showed about 20% energy consumption decrease. Mixture of enzymes with 1.5 kg/t dosage showed about 15% decrease of energy consumption during the refining. Pectinase at different dosages and treatment times did not show significant effect on energy consumption. Results of knowledge discovery in databases showed the xylanase, cellulase and pectinase blend as most promising for energy reduction in TMP process. Surfactants were determined as effective additives for energy saving with enzymes.

Beyond the obvious : three acts in educational drama

Researching research is not a common theme in educational drama. Nor is the educational drama process from a participant perspective a typical focus of research, at least not if the participants are disabled. Yet this is the theme of this thesis, a drama in three acts. The aim of this thesis is to describe, analyse, and discuss both the ways in which research within educational drama can be carried out and represented, and the experiences of the participants of the educational drama process. The theoretical framework that steers the research process is built up of two pairs of frames, each of them, like Russian nesting dolls, containing further frames. The first frame, relating to the outcomes of conducting research in educational drama, comprises philosophical, representational, and personal theories. As the second question asks what educational drama is, the subject related frame is built up of pedagogical, drama educational, and aesthetic theories. The study in its entirety follows the structure of the researcher’s hermeneutical learning process and takes the form of a journey starting from what is familiar, stretching towards what is new and different, and finally returning back to the beginning with a new view on what was there at the start. The thesis consists of two separate but related studies. The first, a familiar study conducted earlier, Alpha in Act I, was carried out among upper secondary school pupils. In the second, the new and therefore unfamiliar study, Omega in Act III, the participants are adult individuals who are physically and communicatively disabled. In between these two Acts an element of “Verfremdung” where the Alpha study is systematically scrutinized as the purpose is to teach and to manage the reader to think. Meta-discussions on the philosophical issues of the study are conducted throughout the text, parallel to the empirical parts. The outcomes of the first research question show that philosophical, methodical, and representational consistency is crucial for research. While this may sound like stating the obvious, this has nevertheless not always been considered fact, especially not within qualitative research. The outcomes further stress that representational issues are also to be recognized when presenting non-rational aspects of educational drama. By wording the world, through the use of visualising language, the surplus of meanings of educational drama can be, as they are within this study, made visible, sensible, and almost tangible, not only cognitively understandable. The outcomes of the second question point to the different foci of the studies, with Alpha focusing on the rationally retold experiences and Omega focusing on nonrational experiences. The outcomes expose educational drama as a learning process comprising doing, reflecting, and being. The doing aspect communicates the concrete efforts in creating a piece of theatre, while the being aspect relates experiences of being as situated, embodied and sensuous, reciprocal, empowering, aesthetic and artistic, and existential. Reflection is the twine that runs throughout the process and connects both doing and being. In summary, the outcomes could be formulated as “learning from learning how to make theatre”.

Happidispersion karakterisointi laboratoriosekoittimessa

Työn tarkoituksena oli tarkastella uutta kuvantamistekniikkaa käyttäen happikaasun dispergointia keskisakeuksisen massasuspension joukkoon laboratoriosekoittimessa. Työssä pyrittiin tarkastelemaan muodostuvan dispersion homogeenisuutta neljästä eri kuvauspisteestä sekoittimen kannesta ja kyljestä. Samalla tarkasteltiin myös sekoittimen tehonkulutusta sekä tehonkulutuksen ja aikaansaadun dispersion välistä yhteyttä. Työn yhtenä tarkoituksena oli myös tarkastella uuden kuvantamistekniikan mahdollisuuksia tämäntyyppisissä sovellutuksissa, sillä työ kuuluu PulpVision-projektiin, jossa kehitetään massa- ja paperiteollisuuden uusia konenäkösovellutuksia. Työn kokeellinen osuus koostui sekoituskokeista, joissa tarkasteltiin neljästä kuvauspisteestä kahdella sekoittimen nopeudella mänty- ja koivususpensioihin muodostuvaa kuplakokojakaumaa. Sekoituskokeiden lisäksi tehtiin tehonkulutuskokeita, joissa tarkasteltiin sekoittimen tehonkulutusta sekoittimen täyttöasteen funktiona koivu- ja mäntysuspensioilla sekä vedellä. Työn tuloksien perusteella todettiin, että koivususpensiosta havaittujen kuplien pinta-ala oli noin puolet mäntysuspensiosta havaittujen kuplien pinta-alasta. Sekoittimen roottorin pyörimisnopeuden puolittuessa suspensioon dispergoidun hapen kuplakoko kasvoi huomattavasti. Neljästä kuvausyhteestä tarkasteltuna havaittiin pienimpien kuplien esiintyvän sekoittimen alaosassa. Mäntysuspension tehonkulutuksen havaittiin kasvavan viidenneksellä, kun sekoittimen täyttöaste kasvoi 10 %, kun taas koivususpension tehonkulutuksen kasvu oli tästä vain puolet. Kuvantamislaitteiston todettiin olevan tämänkaltaiseen sovellutukseen riittävä, varsinkin kun valonlähteenä käytetään pulssilaseria.

Some advances in mathematical models for preference relations

Preference relations, and their modeling, have played a crucial role in both social sciences and applied mathematics. A special category of preference relations is represented by cardinal preference relations, which are nothing other than relations which can also take into account the degree of relation. Preference relations play a pivotal role in most of multi criteria decision making methods and in the operational research. This thesis aims at showing some recent advances in their methodology. Actually, there are a number of open issues in this field and the contributions presented in this thesis can be grouped accordingly. The first issue regards the estimation of a weight vector given a preference relation. A new and efficient algorithm for estimating the priority vector of a reciprocal relation, i.e. a special type of preference relation, is going to be presented. The same section contains the proof that twenty methods already proposed in literature lead to unsatisfactory results as they employ a conflicting constraint in their optimization model. The second area of interest concerns consistency evaluation and it is possibly the kernel of the thesis. This thesis contains the proofs that some indices are equivalent and that therefore, some seemingly different formulae, end up leading to the very same result. Moreover, some numerical simulations are presented. The section ends with some consideration of a new method for fairly evaluating consistency. The third matter regards incomplete relations and how to estimate missing comparisons. This section reports a numerical study of the methods already proposed in literature and analyzes their behavior in different situations. The fourth, and last, topic, proposes a way to deal with group decision making by means of connecting preference relations with social network analysis.