Kvantitatiivisen osakepisteytysmallin testaaminen Euroopan markkinoilla

Tutkielman tavoitteena on testata kvantitatiivisen osakepisteytysmallin tehokkuutta Euroopan osakemarkkinoilla. Osakepisteytysmalli järjestää osakkeet paremmuusjärjestykseen yrityskohtaisten tunnuslukujen avulla. Pisteytysmallin suositusten mukaan luodaan testisalkku ajanjaksolta 2002 2007. Testisalkun tuottoa mitataan pääomahyödykkeiden hinnoittelumallin sekä Faman ja Frenchin kolmen faktorin mallin avulla. Testisalkkua testataan markkina arvopainoisena sekä tasapainoisena. Tasapainoisessa salkussa jokaista osaketta painotetaan yhtäläisesti. Testisalkun rinnalle luodaan lisäksi vertailusalkku satunnaisista osakkeista. Tasapainotettu testisalkku tuotti tarkasteluajanjaksolla tilastollisesti merkitsevää markkinariskikorjattua ylituottoa 0,7 prosenttia kuukaudessa. Kolmen faktorin mallin avulla laskettu ylituotto ei ollut merkitsevä. Yrityskokofaktori sekä markkinatuotto näyttivät selittävän vahvasti testisalkun tuottoja. Yrityskoon vaikutus näkyi myös markkina arvopainotetussa salkussa, jonka tuotto ei päihittänyt markkinatuottoa. Vertailusalkku ei tuottanut tilastollisesti merkitsevää ylituottoa.

Tehokerrointa korjaava skalaariohjaus puoliohjatussa ja kuusikytkintasasuuntaajassa

Verkon harmonisvirtoja rajoittavien standardien tiukentuessa joudutaan etenkin suuritehoisissa tehoelektronisissa laitteissa siirtymään aktiivisiin transistoriohjattuihin tasasuuntaajiin, jotka korjaavat tehokerrointa ja siten pienentävät verkkoon kytkeytyviä häiriövirtoja. Tässä diplomityössä esitellään yleisimpien kolmivaiheisten tasasuuntaajatopologioiden eroja ja vertaillaan puoliohjatun kolmikytkintopologian ja kuusikytkintopologian suorituskykyä tehokertoimen ja harmonissärön osalta, 16 kilowatin teholuokan taajuusmuuttajassa. Tasasuuntaajille tehtiin skalaariohjaukseen perustuva simulointimalli. Työn tavoitteena esitellään simulointitulokset harmonistason sekä tehokertoimen osalta. Työ liittyy Lappeenrannan teknillisen yliopiston sovelletun elektroniikan laboratorion ja Vacon Oyj:n yhteiseen hankkeeseen.

Design and production of protein nanostructures for biomolecular detection

Particulate nanostructures are increasingly used for analytical purposes. Such particles are often generated by chemical synthesis from non-renewable raw materials. Generation of uniform nanoscale particles is challenging and particle surfaces must be modified to make the particles biocompatible and water-soluble. Usually nanoparticles are functionalized with binding molecules (e.g., antibodies or their fragments) and a label substance (if needed). Overall, producing nanoparticles for use in bioaffinity assays is a multistep process requiring several manufacturing and purification steps. This study describes a biological method of generating functionalized protein-based nanoparticles with specific binding activity on the particle surface and label activity inside the particles. Traditional chemical bioconjugation of the particle and specific binding molecules is replaced with genetic fusion of the binding molecule gene and particle backbone gene. The entity of the particle shell and binding moieties are synthesized from generic raw materials by bacteria, and fermentation is combined with a simple purification method based on inclusion bodies. The label activity is introduced during the purification. The process results in particles that are ready-to-use as reagents in bioaffinity. Apoferritin was used as particle body and the system was demonstrated using three different binding moieties: a small protein, a peptide and a single chain Fv antibody fragment that represents a complex protein including disulfide bridge.If needed, Eu3+ was used as label substance. The results showed that production system resulted in pure protein preparations, and the particles were of homogeneous size when visualized with transmission electron microscopy. Passively introduced label was stably associated with the particles, and binding molecules genetically fused to the particle specifically bound target molecules. Functionality of the particles in bioaffinity assays were successfully demonstrated with two types of assays; as labels and in particle-enhanced agglutination assay. This biological production procedure features many advantages that make the process especially suited for applications that have frequent and recurring requirements for homogeneous functional particles. The production process of ready, functional and watersoluble particles follows principles of “green chemistry”, is upscalable, fast and cost-effective.

Assessment of facilitators' design thinking

Meeting design is one of the most critical prerequisites of the success of facilitated meetings but how to achieve the success is not yet fully understood. This study presents a descriptive model of the design of technology supported meetings based on literature findings about the key factors contributing to the success of collaborative meetings, and linking these factors to the meeting design steps by exploring how facilitators consider the factors in practice in their design process. The empirical part includes a multiple-case study conducted among 12 facilitators. The case concentrates on the GSS laboratory at LUT, which has been working on facilitation and GSS for the last fifteen years. The study also includes ‘control’ cases from two comparable institutions. The results of this study highlight both the variances and commonalities among facilitators in how they design collaboration processes. The design thinking of facilitators of all levels of experience is found to be largely consistent wherefore the key design factors as well as their role across the design process can be outlined. Session goals, group composition, supporting technology, motivational aspects, physical constraints, and correct design practices were found to outline the key factors in design thinking. These factors are further categorized into three factor types of controllable, constraining, and guiding design factors, because the study findings indicate the factor type to have an effect on the factor’s importance in design. Furthermore, the order of considering these factors in the design process is outlined.

Valta ja esimiestyö osuuskunnassa

Työn tavoitteena on kuvata ja ymmärtää valtaa ja vallankäyttöä esimiehen näkökulmasta. Tarkoituksena on selvittää, miten valta ilmenee esimiestyössä sekä esimiehen ja alaisten välisissä suhteissa. Tutkimus on luonteeltaan laadullinen tutkimus, jonka tutkimusmenetelmänä käytettiin teemahaastattelua. Tutkimusaineisto kerättiin tekemällä kuusi yksilöhaastattelua OP Pohjola ryhmän osuuspankkeihin. Tutkimusta varten haastateltiin kohdeorganisaation esimiehiä. Haastattelujen osia liitettiin tutkimuksen empfriseen osaan. Tutkimuksen perusteella saatiin selkeä kuva esimiestyöstä ja johtamisesta sekä esimiehen vallankäytöstä kohdeorganisaatiossa. Tutkimustulokset osoittavat, että esimiehet näkevät vallan kuuluvan työhönsä. Valtansa avulla esimiehet vievät organisaatiota kohti sen tavoitteita.

The Role of Surfactant Properties of Extractants in Hydrometallurgical LiquidLiquid Extraction Processes

The amphiphilic nature of metal extractants causes the formation of micelles and other microscopic aggregates when in contact with water and an organic diluent. These phenomena and their effects on metal extraction were studied using carboxylic acid (Versatic 10) and organophosphorus acid (Cyanex 272) based extractants. Special emphasis was laid on the study of phase behaviour in a pre neutralisation stage when the extractant is transformed to a sodium or ammonium salt form. The pre neutralised extractants were used to extract nickel and to separate cobalt and nickel. Phase diagrams corresponding to the pre neutralisation stage in a metal extraction process were determined. The maximal solubilisation of the components in the system water(NH3)/extractant/isooctane takes place when the molar ratio between the ammonia salt form and the free form of the extractant is 0.5 for the carboxylic acid and 1 for the organophosphorus acid extractant. These values correspond to the complex stoichiometry of NH4A•HA and NIi4A, respectively. When such a solution is contacted with water a microemulsion is formed. If the aqueous phase contains also metal ions (e.g. Ni²+), complexation will take place on the microscopic interface of the micellar aggregates. Experimental evidence showing that the initial stage of nickel extraction with pre neutralised Versatic 10 is a fast pseudohomogeneous reaction was obtained. About 90% of the metal were extracted in the first 15 s after the initial contact. For nickel extraction with pre neutralised Versatic 10 it was found that the highest metal loading and the lowest residual ammonia and water contents in the organic phase are achieved when the feeds are balanced so that the stoichiometry is 2NH4+(org) = Nit2+(aq). In the case of Co/Ni separation using pre neutralised Cyanex 272 the highest separation is achieved when the Co/extractant molar ratio in the feeds is 1 : 4 and at the same time the optimal degree of neutralisation of the Cyanex 272 is about 50%. The adsorption of the extractants on solid surfaces may cause accumulation of solid fine particles at the interface between the aqueous and organic phases in metal extraction processes. Copper extraction processes are known to suffer of this problem. Experiments were carried out using model silica and mica particles. It was found that high copper loading, aromacity of the diluent, modification agents and the presence of aqueous phase decrease the adsorption of the hydroxyoxime on silica surfaces.

Capital Structure of Finnish SMEs and Financial Constraints

This thesis studies capital structure of Finnish small and medium sized enterprises. The specific object of the study is to test whether financial constraints have an effect on capital structure. In addition influences of several other factors were studied. Capital structure determinants are formulated based on three capital structure theories. The tradeoff theory and the agency theory concentrate on the search of optimal capital structure. The pecking order theory concerns favouring on financing source over another. The data of this study consists of financial statement data and results of corporate questionnaire. Regression analysis was used to find out the effects of several determinants. Regression models were formed based on the presented theories. Short and long term debt ratios were considered separately. The metrics of financially constrained firms was included in all models. It was found that financial constrains have a negative and significant effect to short term debt ratios. The effect was negative also to long term debt ratio but not statistically significant. Other considerable factors that influenced debt ratios were fixed assets, age, profitability, single owner and sufficiency of internal financing.

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