Tuotelopetukset teleoperaattoriyrityksen tuotteen elinkaaren hallinnassa

Tässä työssä selvitettiin tuotelopetustoiminnan nykytilaa ja tuotteen elinkaaren hallinnan prosessimallin hyödyntämistä suuressa teleoperaattoriyrityksessä. Työn tavoitteena oli tutkia, mitkä tekijät hidastavat lopetuksia ja miten hitaus vaikuttaa alasajojen kustannuksiin. Toisaalta haluttiin selvittää, miten tuotteen elinkaaren prosessimallia käytetään case-yrityksessä erityisesti tuotelopetustoiminnan osalta, ja miten prosessimallin käytöstä voidaan hyötyä. Näiden kysymysten selvittämiseksi haastateltiin kymmentä tuotelopetuksiin osallistunutta tuotevastaavaa yritysasiakas- ja tuotantoyksiköissä, hankittiin tuotetietoa yrityksen useilta asiantuntijoilta ja teoriatietoa muun muassa referenssimalleista ja tuotelopetusstrategioista kirjallisuudesta. Syitä hitaisiin tuotelopetuksiin listattiin. Todettiin, että moniin ongelmiin ratkaisun tarjoaisivat tehokkaampi tuote- ja asiakastiedonhallinta ja lopetettavien tuotteiden tunnistaminen, kypsien tuotteiden tarkempi seuranta sekä myyjien lisäkoulutukset. Joidenkin tuotteiden lopetuksen keston pidentyminen voi lisätä lopetukseen liittyviä kustannuksia, mutta näin ei ole kaikkien tuotteiden kohdalla. Lisäksi todettiin, että osa vanhoista tuotteista ei ole korvattavissa täysin uusilla tuotteilla uusiin tuotteisiin liittyvien riskien vuoksi. Tuloksena selvisi myös, että prosessimallia ei käytetä kaikissa tuotelopetustapauksissa. Syitä tähän on selvitettävä vielä lisätutkimuksin, jotta mallin parantaminen onnistuisi.

Design and Analysis of Forward Error Control Coding and Signaling for Guaranteeing QoS in Wireless Broadcast Systems

Broadcasting systems are networks where the transmission is received by several terminals. Generally broadcast receivers are passive devices in the network, meaning that they do not interact with the transmitter. Providing a certain Quality of Service (QoS) for the receivers in heterogeneous reception environment with no feedback is not an easy task. Forward error control coding can be used for protection against transmission errors to enhance the QoS for broadcast services. For good performance in terrestrial wireless networks, diversity should be utilized. The diversity is utilized by application of interleaving together with the forward error correction codes. In this dissertation the design and analysis of forward error control and control signalling for providing QoS in wireless broadcasting systems are studied. Control signaling is used in broadcasting networks to give the receiver necessary information on how to connect to the network itself and how to receive the services that are being transmitted. Usually control signalling is considered to be transmitted through a dedicated path in the systems. Therefore, the relationship of the signaling and service data paths should be considered early in the design phase. Modeling and simulations are used in the case studies of this dissertation to study this relationship. This dissertation begins with a survey on the broadcasting environment and mechanisms for providing QoS therein. Then case studies present analysis and design of such mechanisms in real systems. The mechanisms for providing QoS considering signaling and service data paths and their relationship at the DVB-H link layer are analyzed as the first case study. In particular the performance of different service data decoding mechanisms and optimal signaling transmission parameter selection are presented. The second case study investigates the design of signaling and service data paths for the more modern DVB-T2 physical layer. Furthermore, by comparing the performances of the signaling and service data paths by simulations, configuration guidelines for the DVB-T2 physical layer signaling are given. The presented guidelines can prove useful when configuring DVB-T2 transmission networks. Finally, recommendations for the design of data and signalling paths are given based on findings from the case studies. The requirements for the signaling design should be derived from the requirements for the main services. Generally, these requirements for signaling should be more demanding as the signaling is the enabler for service reception.

Paineellisten rumpusuodinten kunnossapitostrategian kehittäminen ja implementointi

Tutkimuksen tavoitteena oli luoda UPM-Kymmene Oyj:n Kaukaan sellutehtaalle tuotannolliset näkökulmat huomioiva ja kunnossapitokustannukset optimoiva paineellisten rumpusuodinten kunnossapitostrategia. Paineelliset rumpusuotimet on sellutehtaan kuitulinjan keskeinen laiteryhmä, jonka vuosittaiset kunnossapitokustannukset ovat merkittävät. Tarkastelu työssä keskittyi paineellisen rumpusuotimen päätytiivistyksen kunnossapitostrategian kehittämiseen, koska päätytiivistys muodostaa laitteen vuosittaisista kustannuksista suurimman osan. Kunnossapitokustannusten optimointi suoritettiin strategisen johtamisen periaatteiden mukaisesti eri teknistaloudelliset näkökulmat huomioiden. Kunnossapidon toteutukselle määriteltiin tuotannon tavoitteet, jonka perusteella luotiin uusi kunnossapitostrategia. Työssä tehdyn tutkimuksen perusteella siirtymällä korjaavasta kunnossapidosta ehkäisevään kunnossapitoon, voidaan saavuttaa säästöjä kunnossapitokustannuksissa. Uuden strategian toteutumisen mahdollistamiseksi määriteltiin strategiset projektit, jotka käsittelivät muun muassa uusien tiivistemateriaalien käyttöönottoa, alajärjestelmien muutostöitä sekä toimintatapojen muutoksia. Strategian ja strategisten projektien toteutusta varten laadittiin kirjalliset dokumentit, joiden perusteella implementointi suoritetaan. Toimenpiteille määriteltiin vastuuhenkilöt ja toteutusajat, joiden mukaisesti eri organisaatiotasot toimivat. Strategia laadittiin seuraavalle kymmenelle vuodelle, mutta strategian toteutusta ja tuloksia on seurattava vuosittain. Muuttuvassa liiketoimintaympäristössä kunnossapidon optimitila ei ole staattinen, joten strategiaa on oltava valmis päivittämään. Aktiivisella ja suunnitelmallisella toiminnalla on mahdollista saavuttaa merkittäviä säästöjä tuotannon ja kunnossapidon näkökulmasta.

Financial performance of segments in the intelligent home network

The goal of this study is to examine the intelligent home business network in order to determine which part of the network has the best financial abilities to produce new business models and products/services by using financial statement analysis. A group of 377 studied limited companies is divided into four examined segments based on their offering in producing intelligent homes. The segments are customer service providers, system integrators, subsystem suppliers and component suppliers. Eight different key figures are calculated from each of the companies to get a comprehensive view of their financial performances, after which each of the segments is studied statistically to determine the performances of the whole segments. The actual performance differences between the segments are calculated by using the multi-criteria decision analysis method in which the performances of the key figures are graded and each key figure is weighted according to its importance for the goal of the study. The results of this analysis showed that subsystem suppliers have the best financial performance. Second best are system integrators, third are customer service providers and fourth component suppliers. None of the segments were strikingly poor, but even component suppliers were rather reasonable in their performance; so, it can be said that no part of the intelligent home business network has remarkably inadequate financial abilities to develop new business models and products/services.

Hvordan øve hellige handlinger? : en profesjonsdidaktisk studie av øving av muntlige ferdigheter innenfor en norsk presteutdanning

How can the holy craft of liturgy be trained? A study of approaches to instruction in training oral skills within education of the Norwegian clergy The theme of this study is the competence of expression of clerics performing liturgies as part of their duties in the Norwegian Lutheran Church. The aim of the study is to find a teaching practice which can raise the competence in oral expression characteristic of the clergy profession. The teaching practice is explored and discussed within the context of the basic education of the clergy. The main thesis is formulated as a question: How can the holy craft of liturgy be trained? An underpinning of the study is that liturgical acts are holy, which gives these performances an aspect of otherness. This otherness constitutes a clear agreement between the students and the teacher, and between the professional and the employer. The pre-understanding of the researcher is that these liturgical oral acts are trainable, and that there is a need and a necessity to train in these skills. Three research questions are elaborated on in the explorative section of the study: • What is characteristic of a competence of expression connected to the profession? • How can this competence of expression connected to liturgical performance be developed? • What is the importance of this competence in the holy craft of liturgy for the development of a cohesive professional self-understanding? The study is based on a research and development project where the researcher as the teacher and students from one specific clergy education in Norway (MF) were the source of the empirical material. The empirical data came from practice with two external observers› logs on the coaching, video observations, of the teacher and the students› texts on the practice under study, which is liturgical performance. The researcher›s log and field notes also provide material for the analysis. This is a qualitative project and an arts education project carried out within an interpretative framework. The theoretical framework has three perspectives: a structural approach based on the system theory of Niklas Luhmann, an epistemological approach discussing forms of knowledge in practice or informing practice and an arts education approach. The results indicate that the competence in oral liturgical performance can be considered a trainable skill, and that this training can be understood as an arts education method of instruction based on meaningful communication, dramaturgical thinking and the development of authenticity. The main result from this study can be considered as articulating and sketching the contours of the field of knowledge where the students embody the meaning of the clergy profession ‒ and this articulation has an innovative potential as knowledge combining experience and theoretical understanding.

Kartonkipakkauskoneen dynaaminen kireydenhallinta

Työssä tutkitaan PI-säätimen käyttöä dynaamisessa kireydensäädössä ilman varsinaista kireyden takaisinkytkentää. Kireyttä säädetään epäsuorasti käyttämällä takaisinkytkentätietona kahden telan välistä paikkaeroa. Kireyssäädin toteutetaan nopeussäätimen rinnalle. Rinnakkaisrakenteella pyritään kireyden muutoksiin nopeasti reagoivaan säätöratkaisuun. Rakenne toteutetaan osaksi taajuusmuuttajan säätöketjua. Työssä esitetään telasysteemin simulointimalli, jonka toimivuus varmistetaan käytännön mittauksin. Lisäksi työssä arvioidaan kireyssäädön toimintaa dynaamisessa kireydensäädössä simulointien ja testilaitteistolla suoritettavien mittausten perusteella.

Utilisation of magnetic field in membrane filtration

As it is known, the major problem of membrane filtration is fouling of membrane during the filtration process. There are a lot of methods to prevent or reduce fouling. One very little studied method is applying of magnetic field in membrane filtration. Magnetic field has such advantages as bulk, contact free, nondestructive impact on the sample, thus it can be combined with different types of processes. In addition, the use of magnetic fields has given positive results in various areas of science and life. So, the present thesis is devoted to the research of influence of magnetic field on performances of nanofiltration. In the literature part of the thesis a short description of membrane process and mechanism of reorientation of nanoparticals in magnetic field is presented. The utilization of magnetic field in different spheres of life, in general, and membrane area, in particular, is represented. In the experimental part the influence of magnetic field created by two permanent magnets on filtration of two solutions (citric acid and sodium dodecyl sulfate) was investigated. Factors, which affect on the impact of magnetic field was estimated. The effect of magnetic field was evaluated by measuring a change of pure water permeability after the filtration of model solution. This work demonstrated that direction of magnetic field and the type of molecules of filtered solution has significant effect to the efficiency of nanofiltration. Utilization of magnetic field might increase retention of membrane and flux through membrane and reduce fouling.

"Dov'è la sinistra?" Hemispatial neglect in stroke

As long as the incidence of stroke continues to grow, patients with large right hemisphere lesions suffering from hemispatial neglect will require neuropsychological evaluation and rehabilitation. The inability to process information especially that coming from the left side accompanied by the magnetic orientation to the ipsilesional side represents a real challenge for rehabilitation. This dissertation is concerned with crucial aspects in the clinical neuropsychological practice of hemispatial neglect. In studying the convergence of the visual and behavioural test batteries in the assessment of neglect, nine of the seventeen patients, who completed both the conventional subtests of the Behavioural Inattention Test and the Catherine Bergego Scale assessments, showed a similar severity of neglect and thus good convergence in both tests. However, patients with neglect and hemianopia had poorer scores in the line bisection test and they displayed stronger neglect in behaviour than patients with pure neglect. The second study examined, whether arm activation, modified from the Constraint Induced Movement Therapy, could be applied as neglect rehabilitation alone without any visual training. Twelve acute- or subacute patients were randomized into two rehabilitation groups: arm activation training or traditional voluntary visual scanning training. Neglect was ameliorated significantly or almost significantly in both training groups due to rehabilitation with the effect being maintained for at least six months. In studying the reflections of hemispatial neglect on visual memory, the associations of severity of neglect and visual memory performances were explored. The performances of acute and subacute patients with hemispatial neglect were compared with the performances of matched healthy control subjects. As hypothesized, encoding from the left side and immediate recall of visual material were significantly compromised in patients with neglect. Another mechanism of neglect affecting visual memory processes is observed in delayed visual reproduction. Delayed recall demands that the individual must make a match helped by a cue or it requires a search for relevant material from long-term memory storage. In the case of representational neglect, the search may succeed but the left side of the recollected memory still fails to open. Visual and auditory evoked potentials were measured in 21 patients with hemispatial neglect. Stimuli coming from the left or right were processed differently in both sensory modalities in acute and subacute patients as compared with the chronic patients. The differences equalized during the course of recovery. Recovery from hemispatial neglect was strongly associated with early rehabilitation and with the severity of neglect. Extinction was common in patients with neglect and it did not ameliorate with the recovery of neglect. The presence of pusher symptom hampered amelioration of visual neglect in acute and subacute stroke patients, whereas depression did not have any significant effect in the early phases after the stroke. However, depression had an unfavourable effect on recovery in the chronic phase. In conclusion, the combination of neglect and hemianopia may explain part of the residual behavioural neglect that is no longer evident in visual testing. Further research is needed in order to determine which specific rehabilitation procedures would be most beneficial in patients suffering the combination of neglect and hemianopia. Arm activation should be included in the rehabilitation programs of neglect; this is a useful technique for patients who need bedside treatment in the acute phase. With respect to the deficit in visual memory in association with neglect, the possible mechanisms of lateralized deficit in delayed recall need to be further examined and clarified. Intensive treatment induced recovery in both severe and moderate visual neglect long after the first two to first three months after the stroke.

Application of electrokinetic Fenton process for the remediation of soil contaminated with HCB

Electrokinetic remediation coupled with Fenton oxidation, widely called as Electrokinetic Fenton process is a potential soil remediation technique used for low permeable soil. The applicability of the process has been proved with soil contaminated with a wide range of organic compounds from phenol to the most recalcitrant ones such as PAHs and POPs. This thesis summarizes the major findings observed during an Electrokinetic Fenton Process study conducted for the remediation of low permeable soil contaminated with HCB, a typical hydrophobic organic contaminant. Model low permeable soil, kaolin, was artificially contaminated with HCB and subjected to Electrokinetic Fenton treatments in a series of laboratory scale batch experiments. The use of cyclodextrins as an enhancement agent to mobilize the sorbed contaminant through the system was investigated. Major process hindrances such as the oxidant availability and treatment duration were also addressed. The HCB degradation along with other parameters like soil pH, redox and cumulative catholyte flow were analyzed and monitored. The results of the experiments strengthen the existing knowledge on electrokinetic Fenton process as a promising technology for the treatment of soil contaminated with hydrophobic organic compounds. It has been demonstrated that HCB sorbed to kaolin can be degraded by the use of high concentrations of hydrogen peroxide during such processes. The overall system performances were observed to be influenced by the point and mode of oxidant delivery. Furthermore, the study contributes to new knowledge in shortening the treatment duration by adopting an electrode polarity reversal during the process.

Observations of Industry Momentum Effect in European Equity Indices

This thesis examines the existence and nature of momentum effect in European equity indices. A set of predefined indicators is used to compose momentum portfolios and different holding periods are used to test the strategies over variable time periods as well as under different economical conditions. The data consists of daily closing prices of STOXX Europe 600 index and its 18 super sector indices. Over the study period we follow the performances of a long position in the Winner portfolio, a position in the market neutral zero-cost portfolio and also a position in the risk-controlled zero-cost portfolio. The investment ratio of the risk-controlled zero-cost portfolio is negatively correlated with the realized market volatility. The results show that momentum effect is present in European industries and is most prominent in the short-term. Indicators that are based on short-term performance tend predict the over- and underperformers for the 1-month holding period more reliably than any other indicator/holding period combination. The examination of the strategies under different economical conditions shows that the market neutral approach can create significant returns in times of recession but in times of economic boom the long position in Winner portfolio outperforms the market neutral portfolio by an extensive margin.

Satelliittioskillaattorin jyrsintätyövaiheiden valmistusystävällisyyden analysointi

Tämän tutkimuksen aiheena on satelliittioskillaattorin jyrsintätyövaiheiden valmistusystävällisyyden analysointi. Tutkimuksen viitekehyksenä on DFM (design for manufacturing), johon kaikki päätelmät ja tulokset sidotaan. Tutkimuksen päätavoite on etsiä valmistusteknisiä ratkaisuja, joilla samanaikaisesti parannetaan, sekä oskillaattorin suorituskykyä, että sen valmistettavuutta noudattamalla DFM-sääntöjä. Suorituskyvyn näkökulmasta tärkeintä on oskillaattorin hyvyysluvun maksimointi. Tutkimuksessa käsitellään lyhyesti satelliittioskillaattorin porauksia, pinnoitusta ja asennusta, mutta pääpaino tutkimuksessa on oskillaattorin rungon jyrsintätyövaiheissa. Tässä työssä toteutettiin DFM-analyysi, jonka avulla pystyttiin helpottamaan lukuisia tuotannollisia ongelmia ja onnistuttiin löytämmään keinoja oskillaattorin suorituskyvyn parantamiseksi.

Performance characteristic of moving average trading rules in the Finnish stock market

The thesis examines the profitability of DMAC trading rules in the Finnish stock market over the 1996-2012 period. It contributes to the existing technical analysis literature by comparing for the first time the performance of DMAC strategies based on individual stock trading portfolios to the performance of index trading strategies based on the trading on the index (OMX Helsinki 25) that consists of the same stocks. Besides, the market frictions including transaction costs and taxes are taken into account, and the results are reported from both institutional and individual investor’s perspective. Performance characteristic of DMAC rules are evaluated by simulating 19,900 different trading strategies in total for two non- overlapping 8-year sub-periods, and decomposing the full-sample-period performance of DMAC trading strategies into distinct bullish- and bearish-period performances. The results show that the best DMAC rules have predictive power on future price trends, and these rules are able to outperform buy-and-hold strategy. Although the performance of the DMAC strategies is highly dependent on the combination of moving average lengths, the best DMAC rules of the first sub-period have also performed well during the latter sub-period in the case of individual stock trading strategies. According to the results, the outperformance of DMAC trading rules over buy-and-hold strategy is mostly attributed to their superiority during the bearish periods, and particularly, during stock market crashes.

Skill Development in Music Reading. The Eye-Movement Approach

This dissertation examined skill development in music reading by focusing on the visual processing of music notation in different music-reading tasks. Each of the three experiments of this dissertation addressed one of the three types of music reading: (i) sight-reading, i.e. reading and performing completely unknown music, (ii) rehearsed reading, during which the performer is already familiar with the music being played, and (iii) silent reading with no performance requirements. The use of the eye-tracking methodology allowed the recording of the readers’ eye movements from the time of music reading with extreme precision. Due to the lack of coherence in the smallish amount of prior studies on eye movements in music reading, the dissertation also had a heavy methodological emphasis. The present dissertation thus aimed to promote two major issues: (1) it investigated the eye-movement indicators of skill and skill development in sight-reading, rehearsed reading and silent reading, and (2) developed and tested suitable methods that can be used by future studies on the topic. Experiment I focused on the eye-movement behaviour of adults during their first steps of learning to read music notation. The longitudinal experiment spanned a nine-month long music-training period, during which 49 participants (university students taking part in a compulsory music course) sight-read and performed a series of simple melodies in three measurement sessions. Participants with no musical background were entitled as “novices”, whereas “amateurs” had had musical training prior to the experiment. The main issue of interest was the changes in the novices’ eye movements and performances across the measurements while the amateurs offered a point of reference for the assessment of the novices’ development. The experiment showed that the novices tended to sight-read in a more stepwise fashion than the amateurs, the latter group manifesting more back-and-forth eye movements. The novices’ skill development was reflected by the faster identification of note symbols involved in larger melodic intervals. Across the measurements, the novices also began to show sensitivity to the melodies’ metrical structure, which the amateurs demonstrated from the very beginning. The stimulus melodies consisted of quarter notes, making the effects of meter and larger melodic intervals distinguishable from effects caused by, say, different rhythmic patterns. Experiment II explored the eye movements of 40 experienced musicians (music education students and music performance students) during temporally controlled rehearsed reading. This cross-sectional experiment focused on the eye-movement effects of one-bar-long melodic alterations placed within a familiar melody. The synchronizing of the performance and eye-movement recordings enabled the investigation of the eye-hand span, i.e., the temporal gap between a performed note and the point of gaze. The eye-hand span was typically found to remain around one second. Music performance students demonstrated increased professing efficiency by their shorter average fixation durations as well as in the two examined eye-hand span measures: these participants used larger eye-hand spans more frequently and inspected more of the musical score during the performance of one metrical beat than students of music education. Although all participants produced performances almost indistinguishable in terms of their auditory characteristics, the altered bars indeed affected the reading of the score: the general effects of expertise in terms of the two eye- hand span measures, demonstrated by the music performance students, disappeared in the face of the melodic alterations. Experiment III was a longitudinal experiment designed to examine the differences between adult novice and amateur musicians’ silent reading of music notation, as well as the changes the 49 participants manifested during a nine-month long music course. From a methodological perspective, an opening to research on eye movements in music reading was the inclusion of a verbal protocol in the research design: after viewing the musical image, the readers were asked to describe what they had seen. A two-way categorization for verbal descriptions was developed in order to assess the quality of extracted musical information. More extensive musical background was related to shorter average fixation duration, more linear scanning of the musical image, and more sophisticated verbal descriptions of the music in question. No apparent effects of skill development were observed for the novice music readers alone, but all participants improved their verbal descriptions towards the last measurement. Apart from the background-related differences between groups of participants, combining verbal and eye-movement data in a cluster analysis identified three styles of silent reading. The finding demonstrated individual differences in how the freely defined silent-reading task was approached. This dissertation is among the first presentations of a series of experiments systematically addressing the visual processing of music notation in various types of music-reading tasks and focusing especially on the eye-movement indicators of developing music-reading skill. Overall, the experiments demonstrate that the music-reading processes are affected not only by “top-down” factors, such as musical background, but also by the “bottom-up” effects of specific features of music notation, such as pitch heights, metrical division, rhythmic patterns and unexpected melodic events. From a methodological perspective, the experiments emphasize the importance of systematic stimulus design, temporal control during performance tasks, and the development of complementary methods, for easing the interpretation of the eye-movement data. To conclude, this dissertation suggests that advances in comprehending the cognitive aspects of music reading, the nature of expertise in this musical task, and the development of educational tools can be attained through the systematic application of the eye-tracking methodology also in this specific domain.

Training executive functions in the laboratory and in real life : cognitive consequences of computer-based exercises and bilingualism

The question of the trainability of executive functions and the impact of such training on related cognitive skills has stirred considerable research interest. Despite a number of studies investigating this, the question has not yet been solved. The general aim of this thesis was to investigate two very different types of training of executive functions: laboratory-based computerized training (Studies I-III) and realworld training through bilingualism (Studies IV-V). Bilingualism as a kind of training of executive functions is based on the idea that managing two languages requires executive resources, and previous studies have suggested a bilingual advantage in executive functions. Three executive functions were studied in the present thesis: updating of working memory (WM) contents, inhibition of irrelevant information, and shifting between tasks and mental sets. Studies I-III investigated the effects of computer-based training of WM updating (Study I), inhibition (Study II), and set shifting (Study III) in healthy young adults. All studies showed increased performance on the trained task. More importantly, improvement on an untrained task tapping the trained executive function (near transfer) was seen in Study I and II. None of the three studies showed improvement on untrained tasks tapping some other cognitive function (far transfer) as a result of training. Study I also used PET to investigate the effects of WM updating training on a neurotransmitter closely linked to WM, namely dopamine. The PET results revealed increased striatal dopamine release during WM updating performance as a result of training. Study IV investigated the ability to inhibit task-irrelevant stimuli in bilinguals and monolinguals by using a dichotic listening task. The results showed that the bilinguals exceeded the monolinguals in inhibiting task-irrelevant information. Study V introduced a new, complementary research approach to study the bilingual executive advantage and its underlying mechanisms. To circumvent the methodological problems related to natural groups design, this approach focuses only on bilinguals and examines whether individual differences in bilingual behavior correlate with executive task performances. Using measures that tap the three above-entioned executive functions, the results suggested that more frequent language switching was associated with better set shifting skills, and earlier acquisition of the second language was related to better inhibition skills. In conclusion, the present behavioral results showed that computer-based training of executive functions can improve performance on the trained task and on closely related tasks, but does not yield a more general improvement of cognitive skills. Moreover, the functional neuroimaging results reveal that WM training modulates striatal dopaminergic function, speaking for training-induced neural plasticity in this important neurotransmitter system. With regard to bilingualism, the results provide further support to the idea that bilingualism can enhance executive functions. In addition, the new complementary research approach proposed here provides some clues as to which aspects of everyday bilingual behavior may be related to the advantage in executive functions in bilingual individuals.

Maidon ja heran mikrosuodatus

Työssä selvitettiin uudenaikaisten polymeerikalvojen soveltuvuutta maidon sekä heran mikrosuodatukseen. Kirjallisessa osassa perehdyttiin maidon ja heran koostumuksiin, mikrobikantoihin sekä erilaisiin maidon sekä heran rasvanpoisto- ja puhdistusmenetelmiin. Tämän lisäksi käsiteltiin mikrosuodatusmenetelmiä sekä niiden käyttöä heran ja maidon käsittelyssä meijeriteollisuudessa. Kokeellisessa osassa verrattiin kahdella eri suodatuslaitteistolla keraami- ja polymeerikalvojen suodatusominaisuuksia separoidun raakamaidon sekä heran poikkivirtausmikrosuodatuksessa. Tavoitteena oli erottaa suodatettavista liuoksista mikrobit sekä jäännösrasva ja tuottaa puhdasta, proteiinipitoista maitoa / heraa. Koeajoissa otetuista näytteistä analysoitiin ainesosakoostumus sekä mikrobipitoisuudet. Tuloksista määritettiin retentioarvot ja näiden perusteella vertailtiin polymeeri- ja keraamikalvojen erotustehokkuutta. Lisäksi kalvojen toimivuutta arvioitiin vuoarvojen avulla. Raakamaidon suodatuksissa polymeerikalvot pidättivät täydellisesti tai lähes täydellisesti jäännösrasvan ja mikrobit, mutta myös kaseiiniproteiinin. Tästä syystä yksikään polymeerikalvoista ei sovellu puhtaan maidon suodatukseen. Keraamikalvot soveltuvat tähän selkeästi paremmin ja yksikään toinen testatuista kalvoista ei päässyt samalle tasolle meijeriteollisuudessa jo käytössä olevan Membralox 1,4 μm -keraamikalvon kanssa. Heran suodatuksissa polymeerikalvot pidättivät täydellisesti tai lähes täydellisesti rasvan ja mikrobit, mutta keraamikalvo päästi huomattavasti enemmän haluttuja proteiineja permeaattiin. Membralox 0,8 μm -keraamikalvo pidätti täydellisesti mikrobit, mutta päästi jonkin verran jäännösrasvaa permeaattiin. Näin ollen kalvovalinta on kompromissi permeaatin puhtauden ja proteiinin saannon välillä. Keraamikalvojen vuohäviöt olivat merkittävästi pienemmät kuin polymeerikalvoilla molempien syöttöliuosten kanssa. Lisäksi keraamikalvojen puhdistus oli huomattavasti nopeampaa ja helpompaa. Tästä syystä keraamiset kalvot soveltuvat polymeerisiä paremmin maidon ja heran mikrosuodatukseen.