Final chlorine dioxide stage at near-neutral pH for bleaching eucalypt pulp

It is well known that pH is an important parameter for controlling the eucalyptus pulp bleaching when using the final chlorine dioxide stage, since it affects the effectiveness of the process. Recommendations found in the literature for operating are in the 3.5 to 4.0 range. However, in this paper it was shown that final chlorine dioxide has better performance, with significant brightness gain while also preserving pulp quality, when it is operated at near neutral pH. This result can be explained by the generation of sodium bicarbonate in situ upon adding carbon dioxide at this stage.

Pienten osakeyhtiöiden verosuunnittelu - empiirinen tutkimus

Tutkimuksen aiheeksi valittiin pienten osakeyhtiöiden verosuunnittelu. Tutkimuksen teoreettinen viitekehys perustui aiempaan laskentatoimen empiiriseen verotutkimukseen sekä laskentatoimen kontingenssiteoreettiseen pk-yritystutkimukseen. Tutkimusaineistoa kerättiin kyselytutkimuksella sekä tilinpaatostietokannasta Voitto+. Kyselytutkimukseen valittiin satunnaisotannalla osakeyhtiötä Etelä Suomen läänistä, joiden liikevaihto oli välillä 1 10 milj. euroa. Kyselytutkimukseen vastasi 216 yritystä, jolloin vastausprosentiksi saatiin 21,3. Kerättyä tutkimusaineistoa analysoitiin kvantitatiivisin menetelmin. Pääasiallisina analysointimenetelminä käytettiin pääkomponentti-, klusteri- ja regressioanalyysiä. Tutkimuksen tavoitteeksi asetettiin kokonaiskuvan muodostaminen pienten osakeyhtiöiden verosuunnittelusta, verosuunnittelun asemointi osaksi yrityksen taloushallintoa sekä yritysten erilaisia verosuunnittelustrategioita selittävien tekijöiden tunnistaminen. Tutkimusaineistosta kyettiin tunnistamaan pääkomponenttianalyysillä neljä erilaista verosuunnitteluorientaatiota: valistunut, resursseja panostava, veroa minimoiva sekä vastuuta ulkoistava. Verosuunnitteluorientaatioita kuvaavien muuttujien avulla yritykset jaettiin klusterianalyysilla neljään ryhmään. Yritykset nimettiin ryhmien luonteidensa mukaisesti verosuunnittelun osalta vastuun ulkoistajiksi, veron minimoijiksi, veroneutraaleiksi sekä valistuneiksi. Verosuunnitteluvastuuta ulkoistavien yritysten ryhmään kuului n. 57 % kyselyyn vastanneista yrityksistä. Tulos osoittaa sen, että yritykset ovat verosuunnittelun osalta paljolti riippuvaisia taloushallinnon sidosryhmistä, tilitoimistoista sekä tilintarkastajista. Tulosta voidaan tulkita myös niin, että taloushallinnon sidosryhmien ammattitaito verosuunnittelun osalta on keskeisessä roolissa, kun arvioidaan, miten yritysten välinen tasapuolisuus verotuksen osalta käytännössä toteutuu. Yritysten erilaisia verosuunnitteluorientaatioita, jotka kuvasivat yritysten verosuunnittelustrategioita, ei kyetty kvantitatiivisilla analyyseilla selittämään samoilla muuttujilla kuin yritysten erilaisia johdon laskentatoimen käytänteitä. Tätä havaintoa tulkittiin siten, että vaikka verosuunnittelu on selkeästi osa yrityksen taloushallintoa, sen asema ei ole johdon laskentatoimen käytänteiden tavoin taloushallinnon ytimessä. Tutkimuksessa kyettiin tuottamaan tuloksia, jotka kontribuoivat aiempia laskentatoimen empiirisiä verotutkimuksia, ja joilla on uutuusarvoa käytännön toimijoiden näkökulmasta.

Escala diagramática para a quantificação do complexo de doenças foliares de final de ciclo em soja

A ocorrência das doenças foliares de final de ciclo em soja (Glycine max) causadas pelos fungos Septoria glycines e Cercospora kikuchii é facilmente observada no campo. Entretanto, são necessárias informações precisas sobre a quantificação de danos e perdas na produtividade. A falta de um método padrão de quantificação visual para essas doenças pode levar a estimativas imprecisas da severidade das mesmas, induzindo a conclusões erradas. Com o objetivo de elaborar uma escala diagramática para quantificar a severidade dessas doenças, foram coletadas em campo, folhas apresentando diferentes níveis de severidade. A área de cada folha e sua correspondente severidade foram determinadas e, obedecendo-se a "Lei do estímulo de Weber-Fechner", foi elaborada uma escala com os níveis de severidade de doença: 2,4; 15,2; 25,9; 40,5 e 66,6%. A validação foi realizada por nove avaliadores, sem experiência na avaliação das doenças de final de ciclo, os quais estimaram a severidade de 30 folhas de soja com sintomas destas doenças. A precisão das avaliações variou de acordo com o avaliador (0,84final de ciclo em soja.

Kuka suunnittelee mainokset? Tutkimus mainosalan kulisseista,yhteistyökäytännöistä ja ristiriidoista. Mainonnan suunnittelijan näkökulma

Tutkimus kuvaa tapahtumia mainonnan suunnittelun kulissien takana ja niiden vaikutusta suunnittelutyöhön mainonnan suunnittelijan näkökulmasta. Lähestymistapa on systeemiteoreettinen: tutkimuksessa tarkastellaan sekä mainostoimiston suunnittelijoiden, projektijohtajien ja muiden mainonnan suunnitteluun osallistuvien keskinäistä vuorovaikutusta että mainostoimiston ja mainoksia tilaavan asiakkaan vuorovaikutuksen asettamia rajoja ja mahdollisuuksia. Keskeinen työväline on Kurt Lewinin kentän käsite. Tutkimuksessa se konkretisoituu esitystavaksi mainonnan suunnittelun olennaisista piirteistä, jotka ovat toisistaan riippuvaisia. Tutkimusta pohjustaa ajatus mainonnan suunnittelun perusrakenteesta, joka on riippumaton taloudellisista, yhteiskunnallisista tai mainostoimialan liiketoimintaympäristön muutoksista. Mainostoimistossa työtä tehdään usein ryhmässä. Ydinryhmä muodostuu kirjoittavan ja visuaalisen suunnittelijan työparista, mutta projektijohtaja on avainasemassa hoitaessaan yhteydenpitoa mainostoimiston asiakkaaseen. Tutkimustyötä viitoittivat kysymykset mainonnan suunnittelijoiden tehtävästä ja asemasta, työssä koetuista haasteista sekä osuudesta ja vastuusta lopullisissa töissä. Keskiössä ovat suunnittelutyötä raamittavat haasteet, jotka ohjaavat suunnittelijoiden kykyjä ja haluja toteuttaa luovuuttaan. Tutkimus ammentaa teoreettisia aineksia työnjaon ja tiimityön käsitteiden ohella vallan tilanteisuudesta ja suhteista sekä sosiaalisen pääoman ja luottamuksen moniaineksisuudesta. Tutkimuksen aineisto kerättiin syksyllä 2008 ja alkuvuodesta 2009 haastattelemalla suomalaisten mainostoimistojen suunnittelijoita. Haastatteluaineisto koostuu kymmenestä ryhmähaastattelusta, johon kuhunkin osallistui 3–4 suunnittelijaa. Muu aineisto sisältää toimialan tilastoja ja julkaisuja sekä yksityisiä sähköpostikirjeenvaihtoja ja keskusteluja mainosammattilaisten kanssa. Haastatteluaineisto analysoitiin Milesin ja Hubermannin aineistolähtöisen sisällönanalyysin avulla ja sitä täydennettiin retorisella diskurssianalyysilla. Analyysin alkuvaiheessa koemetodina sovellettiin Straussin ja Corbinin aineistolähtöisen teorian (grounded theory) kolmivaiheista koodausta. Tutkimuksen tuloksena on malli mainonnan suunnittelun kentän jännitteistä, jotka johtavat toimimaan tietyllä tavalla. Mainonnan suunnittelijan tehtävinä näyttäytyvät vaikuttaminen, asiakkaan tarpeiden tunnistaminen ja tyydyttäminen sekä omakohtainen menestyminen. Suunnittelijan asema näyttää työssä koettujen haasteiden kautta häilyvän asiantuntijuuden ja alihankkijuuden välimaastossa. Työn henkilökohtaisina haasteina piirtyvät tarmokkuuden ja jatkuvan oivaltamisen vaateet. Ulkoisina tekijöinä talouden, teknologian ja sen myötä median murros sekä haastaa että kehittää: alituiseen kiireeseen näytetään verhoavan pulmia, joiden todellinen alkuperä paikantuu muualle. Keskeiset ristiriidat ja toiminnan edellytykset ilmenevät juuri yhteistyössä: mainostoimiston sisäinen yhteistyö ja asiakkaan antama palaute ovat merkittäviä tekijöitä luottamuksen taustalla. Siten avoin ja vastavuoroinen kommunikaatio piirtyy olennaiseksi asetettujen tavoitteiden saavuttamisessa ja asiakkaan menestymisessä. Mainonnan suunnittelussa tärkeäksi kysymykseksi nousevat portinvartijoiden roolit. Mainostoimiston sisäisessä työskentelyssä projektijohtajat hallinnoivat suunnitteluresursseja, välittävät tietoa asiak kaalta suunnittelijalle ja päinvastoin sekä tekevät tärkeimmät päätökset. Asiakkaan puolella mainoksia tilaava asiakashenkilö hallinnoi valjastamiaan resursseja, mutta varsinainen päätöksenteko tapahtuu tämän esimiehen toimesta. Tulosten valossa on perusteltua uskoa, että mainonnan suunnittelijat kokevat oman työnsä arvon alentuneen ja päätösvaltansa vähentyneen. Mainostoimialan murroksen kannalta tutkimus tuo esiin uudenlaisen tiimityön ymmärtämisen ja korostaa yksilöiden vahvuuksien tunnistamisen merkitystä. Kiristyvässä taloudessa se suuntaa huomion sekä mainostoimistojen että niiden asiakasyritysten sisäisten ja ulkoisten resurssien tehokkaaseen ja tuottavaan hyödyntämiseen ja organisoimiseen. Sosiologisesti tutkimus tarjoaa yhdenlaisen näkökulman ryhmätyön ulottuvuuksiin ja työelämän yhteistyöhaasteiden pohtimiseen. Siten tutkimuksen tuloksilla voi nähdä arvoa myös muiden kuin mainosalan yhteistyökäytäntöjentarkasteluun.

Phase voltage control and filtering in a converter-fed single-phase customer-end system of the LVDC distribution network

In recent years, the network vulnerability to natural hazards has been noticed. Moreover, operating on the limits of the network transmission capabilities have resulted in major outages during the past decade. One of the reasons for operating on these limits is that the network has become outdated. Therefore, new technical solutions are studied that could provide more reliable and more energy efficient power distributionand also a better profitability for the network owner. It is the development and price of power electronics that have made the DC distribution an attractive alternative again. In this doctoral thesis, one type of a low-voltage DC distribution system is investigated. Morespecifically, it is studied which current technological solutions, used at the customer-end, could provide better power quality for the customer when compared with the current system. To study the effect of a DC network on the customer-end power quality, a bipolar DC network model is derived. The model can also be used to identify the supply parameters when the V/kW ratio is approximately known. Although the model provides knowledge of the average behavior, it is shown that the instantaneous DC voltage ripple should be limited. The guidelines to choose an appropriate capacitance value for the capacitor located at the input DC terminals of the customer-end are given. Also the structure of the customer-end is considered. A comparison between the most common solutions is made based on their cost, energy efficiency, and reliability. In the comparison, special attention is paid to the passive filtering solutions since the filter is considered a crucial element when the lifetime expenses are determined. It is found out that the filter topology most commonly used today, namely the LC filter, does not provide economical advantage over the hybrid filter structure. Finally, some of the typical control system solutions are introduced and their shortcomings are presented. As a solution to the customer-end voltage regulation problem, an observer-based control scheme is proposed. It is shown how different control system structures affect the performance. The performance meeting the requirements is achieved by using only one output measurement, when operating in a rigid network. Similar performance can be achieved in a weak grid by DC voltage measurement. An additional improvement can be achieved when an adaptive gain scheduling-based control is introduced. As a conclusion, the final power quality is determined by a sum of various factors, and the thesis provides the guidelines for designing the system that improves the power quality experienced by the customer.

Eye Fundus Image Analysis for Automatic Detection of Diabetic Retinopathy

Diabetes is a rapidly increasing worldwide problem which is characterised by defective metabolism of glucose that causes long-term dysfunction and failure of various organs. The most common complication of diabetes is diabetic retinopathy (DR), which is one of the primary causes of blindness and visual impairment in adults. The rapid increase of diabetes pushes the limits of the current DR screening capabilities for which the digital imaging of the eye fundus (retinal imaging), and automatic or semi-automatic image analysis algorithms provide a potential solution. In this work, the use of colour in the detection of diabetic retinopathy is statistically studied using a supervised algorithm based on one-class classification and Gaussian mixture model estimation. The presented algorithm distinguishes a certain diabetic lesion type from all other possible objects in eye fundus images by only estimating the probability density function of that certain lesion type. For the training and ground truth estimation, the algorithm combines manual annotations of several experts for which the best practices were experimentally selected. By assessing the algorithm’s performance while conducting experiments with the colour space selection, both illuminance and colour correction, and background class information, the use of colour in the detection of diabetic retinopathy was quantitatively evaluated. Another contribution of this work is the benchmarking framework for eye fundus image analysis algorithms needed for the development of the automatic DR detection algorithms. The benchmarking framework provides guidelines on how to construct a benchmarking database that comprises true patient images, ground truth, and an evaluation protocol. The evaluation is based on the standard receiver operating characteristics analysis and it follows the medical practice in the decision making providing protocols for image- and pixel-based evaluations. During the work, two public medical image databases with ground truth were published: DIARETDB0 and DIARETDB1. The framework, DR databases and the final algorithm, are made public in the web to set the baseline results for automatic detection of diabetic retinopathy. Although deviating from the general context of the thesis, a simple and effective optic disc localisation method is presented. The optic disc localisation is discussed, since normal eye fundus structures are fundamental in the characterisation of DR.

Introduktionen av kärnkraften i Finland

Finlands industri har av tradition varit starkt energikrävande. Träförädlingsindustrin, som fick sin egentliga start i medlet på 1800-talet, använde stora mängder energi liksom metallförädlingsföretagen i ett senare skede. Krigstiden med sin energiransonering visade handgripligen för allmänheten liksom för specialisterna att en tillräcklig tillgång till energi är ett livsvillkor för vår industri och därmed för vårt land. Efterkrigstiden kännetecknades av en allt snabbare utbyggnad av den på vatten- och ångkraft baserade elkraftskapaciteten, en utbyggnad som den inhemska verkstadsindustrin i stor utsträckning deltog i. Men redan på 1950-talet var vattenkraften till stor del utbyggd, varför den privata såväl som den statliga sektorns intresse allt mera inriktade sig på den speciellt i USA favoriserade atomenergin. Efter fördjupade studier i kärnfysik och kärnteknik vid the International School of Nuclear Science and Engineering i USA deltog författaren av dessa rader intensivt (först som Ahlströmanställd och senare som VD för Finnatom) i den utvecklingsverksamhet inom det kärntekniska området som inte bara elproducenterna utan även verkstadsindustrin i vårt land genomförde. Det var därför naturligt för mig att som objekt för min doktorsavhandling välja introduktionen av kärnkraften i Finland med speciell fokus på den inhemska verkstadsindustrins roll. Jag ställde följande forskningsfrågor: a. När och hur skedde introduktionen av kärnkraften i Finland? b. Vilka var orsakerna till och resultatet av denna introduktion? c. Vilken var den inhemska verkstadsindustrins roll? Ett grundligt studium av litteraturen inklusive mötesprotokoll och tidningsreferat samt personligen genomförda intervjuer med ett trettiotal av de verkliga aktörerna i den långa och komplicerade introduktionsprocessen ledde till en teori, vars riktighet jag anser mig ha kunnat bevisa. Den inhemska verkstadsindustrins roll var synnerligen central. Dess representanter lyckades, bl.a. refererande till erfarenheterna från utbyggnaden av vatten- och ångkraften liksom till byggandet av den underkritiska milan YXP samt forskningsreaktorn TRIGA, övertyga beslutsfattarna om att den besatt nödig kompetens för att kompensera den kompetensbrist som kunde iakttas inom vissa områden hos den sovjetiska kärnkraftverksleverantören. De inhemska leveranserna påverkade även driftsresultatet, speciellt i fallet Lovisa, i positiv riktning. Introduktionsprocessen, som omfattade tiden från slutet av 1950-talet till början på 1980-talet, beskrevs, noterande bl.a. J. W. Creswells anvisningar, i detalj i avhandlingen. Introduktionen fick som resultat konkurrenskraftig elkraft, impuls till start av nya företag, exempelvis Nokia Elektronik, liksom en klar höjning av den tekniska nivån hos vår industri, inkluderande kärnteknisk tillverkning i stor skala. Katastrofen i Tjernobyl i slutet av april 1986 innebar emellertid att utvecklingen tog en paus på ett par decennier. Erfarenheterna från introduktionsfasen kan förhoppningsvis utnyttjas till fullo nu, när utbyggnaden av kärnkraften återupptagits i vårt land.

The cultural dimension in focus : promoting awareness of diversity and respect for difference in a Finland-Swedish EFL classroom

This study addresses the role of EFL education, its potential and shortcomings, and the challenges the future of EFL education will bring. It is argued that new societal demands and the limited time we have at our disposal in the classroom make it necessary to rethink goals and content and move away from the transmissionof limited sets of facts and information to helping students develop awareness and competences that can be applied in many different situations, also in a perspective of lifelong learning. The overall aim of the current study is to problematize and increase understanding of the implementation of cultural aspects in the language classroom by addressing the interrelated what, why and how of the cultural dimension within EFL education. This has been conducted by means of theoretical explorations into the area, alongside an attempt at promoting intercultural competence (IC) in a more systematic and insightful manner within my own educational praxis. The focus of the intercultural work in the classroom was on the promotion of awareness of difference and diversity, as well as respect for such difference through the ability to decenter from cultural norms and behavior that previously have been taken for granted. These are two elements that have been suggested as fundamental for other work with IC in the classroom and for the realization of important aspects of the underlying values of basic education. In the context of this study, IC comprises several interconnected components supportingeach other in a variety of ways, with the further aim being interaction with and respect for difference in general, not only concerning e.g. representatives ofcertain English-speaking communities. The methodology was informed by action research, with myself in the role of the teacher-researcher or the reflective practitioner. For the purpose of the project I was authorized to take on the EFL education for the three years of upper comprehensive school of one random class of students originally assigned to one of the language teachers of the selected Finland-Swedish school. Thus, the class of 17 students was not specifically chosen for the project, and the aims and contents chosen for the development project were placed within the framework of the ordinary curriculum. By exploring the students¿ insights concerning different English-speaking cultural groups, mainly through a set of questionnaires, it was possible to outline the work with the cultural dimension in the classroom for the following three years. Work progress was evaluated at specific stages, and the final project evaluations were conducted through individual student interviews in grade 9. The interviews were focused on possible development of students¿ insights concerning different aspects of the cultural dimension. In particular this concerned awareness of difference and diversity, including modification of stereotypes, as well as the ability to decenterin order to be better able to respect such difference. I also explored students¿ awareness and views of the activities and approaches used in class, as well asaffordances both inside and outside the EFL classroom in relation to these intended insights. A further focus area was the perceived relevance to students of different aspects of the cultural dimension. The frameworks and approaches adopted for the work in the classroom all have in common that they are based on a constructivist framework, where knowledge is constructed and reconstructed through interaction with one¿s social and cultural environment, including interaction with others. Reflective processes precede or are simultaneous with the learning of basic factual knowledge. This entails a view of learning as a progression from simple to more complex models rather than as a progression from facts to understanding and analysis. Here, the development of intercultural competence is seen asa cyclical process, or along a spiral curriculum, from simple to more complex levels through a combination of cognitive, affective and behavioral elements within a framework of experiential learning. This project has shown one possible wayforward concerning the development of intercultural competence within EFL education through a more systematic and comprehensive approach regarding linguistic and cultural aspects. The evaluation of the educational process explored in the study suggests the possibilities for work with the promotion of awareness of difference and diversity concerning some specific context that, based on students¿ prior knowledge and preconceptions, would benefit from further work. In this case, the specific context primarily concerned different aspects of both cultural and linguistic conditions in the UK. It is also suggested that many students developed the ability to decenter, described in the study as integral to being able to respect otherness. What still remains to be explored are more individualized approaches considering students¿ different levels of departure. Further work alsoneeds to be put into how to apply insights gained in these specific situations to more general contexts. It is also necessary to explore the use of the suggested approaches in a wider range of different contexts.

Equivalence and translation strategies in multilingual thesaurus construction

In the present dissertation, multilingual thesauri were approached as cultural products and the focus was twofold: On the empirical level the focus was placed on the translatability of certain British-English social science indexing terms into the Finnish language and culture at a concept, a term and an indexing term level. On the theoretical level the focus was placed on the aim of translation and on the concept of equivalence. In accordance with modern communicative and dynamic translation theories the interest was on the human dimension. The study is qualitative. In this study, equivalence was understood in a similar way to how dynamic, functional equivalence is commonly understood in translation studies. Translating was seen as a decision-making process, where a translator often has different kinds of possibilities to choose in order to fulfil the function of the translation. Accordingly, and as a starting point for the construction of the empirical part, the function of the source text was considered to be the same or similar to the function of the target text, that is, a functional thesaurus both in source and target context. Further, the study approached the challenges of multilingual thesaurus construction from the perspectives of semantics and pragmatics. In semantic analysis the focus was on what the words conventionally mean and in pragmatics on the ‘invisible’ meaning - or how we recognise what is meant even when it is not actually said (or written). Languages and ideas expressed by languages are created mainly in accordance with expressional needs of the surrounding culture and thesauri were considered to reflect several subcultures and consequently the discourses which represent them. The research material consisted of different kinds of potential discourses: dictionaries, database records, and thesauri, Finnish versus British social science researches, Finnish versus British indexers, simulated indexing tasks with five articles and Finnish versus British thesaurus constructors. In practice, the professional background of the two last mentioned groups was rather similar. It became even more clear that all the material types had their own characteristics, although naturally not entirely separate from each other. It is further noteworthy that the different types and origins of research material were not used to represent true comparison pairs, and that the aim of triangulation of methods and material was to gain a holistic view. The general research questions were: 1. Can differences be found between Finnish and British discourses regarding family roles as thesaurus terms, and if so, what kinds of differences and which are the implications for multilingual thesaurus construction? 2. What is the pragmatic indexing term equivalence? The first question studied how the same topic (family roles) was represented in different contexts and by different users, and further focused on how the possible differences were handled in multilingual thesaurus construction. The second question was based on findings of the previous one, and answered to the final question as to what kinds of factors should be considered when defining translation equivalence in multilingual thesaurus construction. The study used multiple cases and several data collection and analysis methods aiming at theoretical replication and complementarity. The empirical material and analysis consisted of focused interviews (with Finnish and British social scientists, thesaurus constructors and indexers), simulated indexing tasks with Finnish and British indexers, semantic component analysis of dictionary definitions and translations, coword analysis and datasets retrieved in databases, and discourse analysis of thesauri. As a terminological starting point a topic and case family roles was selected. The results were clear: 1) It was possible to identify different discourses. There also existed subdiscourses. For example within the group of social scientists the orientation to qualitative versus quantitative research had an impact on the way they reacted to the studied words and discourses, and indexers placed more emphasis on the information seekers whereas thesaurus constructors approached the construction problems from a more material based solution. The differences between the different specialist groups i.e. the social scientists, the indexers and the thesaurus constructors were often greater than between the different geo-cultural groups i.e. Finnish versus British. The differences occurred as a result of different translation aims, diverging expectations for multilingual thesauri and variety of practices. For multilingual thesaurus construction this means severe challenges. The clearly ambiguous concept of multilingual thesaurus as well as different construction and translation strategies should be considered more precisely in order to shed light on focus and equivalence types, which are clearly not self-evident. The research also revealed the close connection between the aims of multilingual thesauri and the pragmatic indexing term equivalence. 2) The pragmatic indexing term equivalence is very much context-depended. Although thesaurus term equivalence is defined and standardised in the field of library and information science (LIS), it is not understood in one established way and the current LIS tools are inadequate to provide enough analytical tools for both constructing and studying different kinds of multilingual thesauri as well as their indexing term equivalence. The tools provided in translation science were more practical and theoretical, and especially the division of different meanings of a word provided a useful tool in analysing the pragmatic equivalence, which often differs from the ideal model represented in thesaurus construction literature. The study thus showed that the variety of different discourses should be acknowledged, there is a need for operationalisation of new types of multilingual thesauri, and the factors influencing pragmatic indexing term equivalence should be discussed more precisely than is traditionally done.

Qualidade de vida em estudantes de Medicina no início e final do curso: avaliação pelo Whoqol-bref

O objetivo do estudo é comparar a qualidade de vida de estudantes de Medicina do primeiro período e do último período do curso. Foi realizado um estudo transversal com a aplicação do instrumento da Organização Mundial da Saúde para avaliação da qualidade de vida no seu formato curto (Whoqol-bref) em 370 estudantes de Medicina da cidade do Recife, Brasil - 229 do primeiro e 141 do último período. Os resultados mostraram que os escores do domínio psicológico foram menores nos alunos do último período do que nos do primeiro período (p < 0,005). Essa diferença se manteve após a análise pelo modelo de covariância (Ancova). Em relação aos escores do domínio físico, relações sociais e meio ambiente, não houve diferenças significativas entre os alunos do primeiro e do último período. Quanto à autoavaliação da qualidade de vida, os alunos do primeiro período apresentaram melhores resultados (3,87 vs. 3,39; p < 0,001). Quanto à satisfação com a própria saúde, não houve diferença estatística; 3,94 vs. 3,62 (p = 0,099). Em conclusão, a qualidade de vida dos estudantes de Medicina, quando avaliada pelo instrumento Whoqol-bref, sofre desgastes no domínio psicológico durante o curso médico. Novos estudos são necessários para identificar os fatores que determinam essas alterações na qualidade de vida dos estudantes de Medicina durante a graduação.

Tutoria em escola médica: avaliação por discentes após seu término e ao final do curso

Na Faculdade de Medicina da UFMG, a tutoria, no formato mentoring, vincula-se ao Núcleo de Apoio Psicopedagógico ao Estudante e é atividade obrigatória. Como em outras escolas médicas, propõe ser um espaço de acolhimento ao estudante no início do ciclo profissional. O objetivo deste trabalho é avaliar, na visão do estudante, a relevância da tutoria em sua formação e as características comuns aos vários grupos. Foram aplicados questionários com perguntas fechadas e abertas aos estudantes do 6º, 11º e 12º períodos do curso médico, com análise descritiva dos resultados quantitativos e análise de conteúdo das questões abertas. Participaram da pesquisa 81% dos estudantes do sexto período e 51% do sexto ano. Houve controvérsia sobre a relevância da atividade, muitas vezes relacionada com obrigatoriedade e inadequação dos tutores, imediatamente após a mesma e ao final do curso. A necessidade de espaço para discutir temas não relacionados com a formação médica puramente técnica também foi salientada. Numa perspectiva geral, a tutoria é atividade importante no quadro curricular, mas é urgente aprimorar o programa, a seleção e a formação dos tutores.

Enhancing performance of paper coatings by tailor-made plastic pigments

The paper industry is constantly looking for new ideas for improving paper products while competition and raw material prices are increasing. Many paper products are pigment coated. Coating layer is the top layer of paper, thus by modifying coating pigment also the paper itself can be altered and value added to the final product. In this thesis, synthesis of new plastic and hybrid pigments and their performance in paper and paperboard coating is reported. Two types of plastic pigments were studied: core-shell latexes and solid beads of maleimide copolymers. Core-shell latexes with partially crosslinked hydrophilic polymer core of poly(n-butyl acrylate-co-methacrylic acid) and a hard hydrophobic polystyrene shell were prepared to improve the optical properties of coated paper. In addition, the effect of different crosslinkers was analyzed and the best overall performance was achieved by the use of ethylene glycol dimethacrylate (EGDMA). Furthermore, the possibility to modify core-shell latex was investigated by introducing a new polymerizable optical brightening agent, 1-[(4-vinylphenoxy)methyl]-4-(2-henylethylenyl)benzene which gave promising results. The prepared core-shell latex pigments performed smoothly also in pilot coating and printing trials. The results demonstrated that by optimizing polymer composition, the optical and surface properties of coated paper can be significantly enhanced. The optimal reaction conditions were established for thermal imidization of poly(styrene-co-maleimide) (SMI) and poly(octadecene-co-maleimide) (OMI) from respective maleic anhydride copolymer precursors and ammonia in a solvent free process. The obtained aqueous dispersions of nanoparticle copolymers exhibited glass transition temperatures (Tg) between 140-170ºC and particle sizes from 50-230 nm. Furthermore, the maleimide copolymers were evaluated in paperboard coating as additional pigments. The maleimide copolymer nanoparticles were partly imbedded into the porous coating structure and therefore the full potential of optical property enhancement for paperboard was not achieved by this method. The possibility to modify maleimide copolymers was also studied. Modifications were carried out via N-substitution by replacing part of the ammonia in the imidization reaction with amines, such as triacetonediamine (TAD), aspartic acid (ASP) and fluorinated amines (2,2,2- trifluoroethylamine, TFEA and 2,2,3,3,4,4,4-heptafluorobuthylamine, HFBA). The obtained functional nanoparticles varied in size between 50-217 nm and their Tg from 150-180ºC. During the coating process the produced plastic pigments exhibited good runnability. No significant improvements were achieved in light stability with TAD modified copolymers whereas nanoparticles modified with aspartic acid and those containing fluorinated groups showed the desired changes in surface properties of the coated paperboard. Finally, reports on preliminary studies with organic-inorganic hybrids are presented. The hybrids prepared by an in situ polymerization reaction consisted of 30 wt% poly(styrene- co-maleimide) (SMI) and high levels of 70 wt% inorganic components of kaolin and/or alumina trihydrate. Scanning Electron Microscopy (SEM) images and characterization by Fourier Transform Infrared Spcetroscopy (FTIR) and X-Ray Diffraction (XRD) revealed that the hybrids had conventional composite structure and inorganic components were covered with precipitated SMI nanoparticles attached to the surface via hydrogen bonding. In paper coating, the hybrids had a beneficial effect on increasing gloss levels.

Multifrequency VLBI Observations of Selected Active Galactic Nuclei

In this dissertation, active galactic nuclei (AGN) are discussed, as they are seen with the high-resolution radio-astronomical technique called Very Long Baseline Interferometry (VLBI). This observational technique provides very high angular resolution (_ 10−300 = 1 milliarcsecond). VLBI observations, performed at different radio frequencies (multi-frequency VLBI), allow to penetrate deep into the core of an AGN to reveal an otherwise obscured inner part of the jet and the vicinity of the AGN’s central engine. Multi-frequency VLBI data are used to scrutinize the structure and evolution of the jet, as well as the distribution of the polarized emission. These data can help to derive the properties of the plasma and the magnetic field, and to provide constraints to the jet composition and the parameters of emission mechanisms. Also VLBI data can be used for testing the possible physical processes in the jet by comparing observational results with results of numerical simulations. The work presented in this thesis contributes to different aspects of AGN physics studies, as well as to the methodology of VLBI data reduction. In particular, Paper I reports evidence of optical and radio emission of AGN coming from the same region in the inner jet. This result was obtained via simultaneous observations of linear polarization in the optical and in radio using VLBI technique of a sample of AGN. Papers II and III describe, in detail, the jet kinematics of the blazar 0716+714, based on multi-frequency data, and reveal a peculiar kinematic pattern: plasma in the inner jet appears to move substantially faster that that in the large-scale jet. This peculiarity is explained by the jet bending, in Paper III. Also, Paper III presents a test of the new imaging technique for VLBI data, the Generalized Maximum Entropy Method (GMEM), with the observed (not simulated) data and compares its results with the conventional imaging. Papers IV and V report the results of observations of the circularly polarized (CP) emission in AGN at small spatial scales. In particular, Paper IV presents values of the core CP for 41 AGN at 15, 22 and 43 GHz, obtained with the help of the standard Gain transfer (GT) method, which was previously developed by D. Homan and J.Wardle for the calibration of multi-source VLBI observations. This method was developed for long multi-source observations, when many AGN are observed in a single VLBI run. In contrast, in Paper V, an attempt is made to apply the GT method to single-source VLBI observations. In such observations, the object list would include only a few sources: a target source and two or three calibrators, and it lasts much shorter than the multi-source experiment. For the CP calibration of a single-source observation, it is necessary to have a source with zero or known CP as one of the calibrators. If the archival observations included such a source to the list of calibrators, the GT could also be used for the archival data, increasing a list of known AGN with the CP at small spatial scale. Paper V contains also calculation of contributions of different sourced of errors to the uncertainty of the final result, and presents the first results for the blazar 0716+714.

Recovery and refining of manganese as by-product from hydrometallurgical processes

The consumption of manganese is increasing, but huge amounts of manganese still end up in waste in hydrometallurgical processes. The recovery of manganese from multi-metal solutions at low concentrations may not be economical. In addition, poor iron control typically prevents the production of high purity manganese. Separation of iron from manganese can be done with chemical precipitation or solvent extraction methods. Combined carbonate precipitation with air oxidation is a feasible method to separate iron and manganese due to the fast kinetics, good controllability and economical reagents. In addition the leaching of manganese carbonate is easier and less acid consuming than that of hydroxide or sulfide precipitates. Selective iron removal with great efficiency from MnSO4 solution is achieved by combined oxygen or air oxidation and CaCO3 precipitation at pH > 5.8 and at a redox potential of > 200 mV. In order to avoid gypsum formation, soda ash should be used instead of limestone. In such case, however, extra attention needs to be paid on the reagents mole ratios in order to avoid manganese coprecipitation. After iron removal, pure MnSO4 solution was obtained by solvent extraction using organophosphorus reagents, di-(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4- trimethylpentyl)phosphinic acid (CYANEX 272). The Mn/Ca and Mn/Mg selectivities can be increased by decreasing the temperature from the commonly used temperatures (40 –60oC) to 5oC. The extraction order of D2EHPA (Ca before Mn) at low temperature remains unchanged but the lowering of temperature causes an increase in viscosity and slower phase separation. Of these regents, CYANEX 272 is selective for Mn over Ca and, therefore, it would be the better choice if there is Ca present in solution. A three-stage Mn extraction followed by a two-stage scrubbing and two-stage sulfuric acid stripping is an effective method of producing a very pure MnSO4 intermediate solution for further processing. From the intermediate MnSO4 some special Mn- products for ion exchange applications were synthesized and studied. Three types of octahedrally coordinated manganese oxide materials as an alternative final product for manganese were chosen for synthesis: layer structured Nabirnessite, tunnel structured Mg-todorokite and K-kryptomelane. As an alternative source of pure MnSO4 intermediate, kryptomelane was synthesized by using a synthetic hydrometallurgical tailings. The results show that the studied OMS materials adsorb selectively Cu, Ni, Cd and K in the presence of Ca and Mg. It was also found that the exchange rates were reasonably high due to the small particle dimensions. Materials are stable in the studied conditions and their maximum Cu uptake capacity was 1.3 mmol/g. Competitive uptake of metals and acid was studied using equilibrium, batch kinetic and fixed-bed measurements. The experimental data was correlated with a dynamic model, which also accounts for the dissolution of the framework manganese. Manganese oxide micro-crystals were also bound onto silica to prepare a composite material having a particle size large enough to be used in column separation experiments. The MnOx/SiO2 ratio was found to affect significantly the properties of the composite. The higher the ratio, the lower is the specific surface area, the pore volume and the pore size. On the other hand, higher amount of silica binder gives composites better mechanical properties. Birnesite and todorokite can be aggregated successfully with colloidal silica at pH 4 and with MnO2/SiO2 weight ratio of 0.7. The best gelation and drying temperature was 110oC and sufficiently strong composites were obtained by additional heat-treatment at 250oC for 2 h. The results show that silica–supported MnO2 materials can be utilized to separate copper from nickel and cadmium. The behavior of the composites can be explained reasonably well with the presented model and the parameters estimated from the data of the unsupported oxides. The metal uptake capacities of the prepared materials were quite small. For example, the final copper loading was 0.14 mmol/gMnO2. According to the results the special MnO2 materials are potential for a specific environmental application to uptake harmful metal ions.