L'Univers

1894/12/14 (Numéro 9683).

L'Univers

1883/12/14 (Numéro 5867).

Electroactive ion exchange membranes based on conducting polymers

Ion exchange membranes are indispensable for the separation of ionic species. They can discriminate between anions and cations depending on the type of fixed ionic group present in the membrane. These conventional ion exchange membranes (CIX) have exceptional ionic conductivity, which is advantageous in various electromembrane separation processes such as electrodialysis, electrodeionisation and electrochemical ion exchange. The main disadvantage of CIX membranes is their high electrical resistance owing to the fact that the membranes are electronically non conductive. An alternative can be electroactive ion exchange membranes, which are ionically and electronically conducting. Polypyrrole (PPy) is a type of electroactive ion exchange material as well as a commonly known conducting polymer. When PPy membranes are repeatedly reduced and oxidised, ions are pumped through the membrane. The main aim of this thesis was to develop electroactive cation transport membranes based on PPy for the selective transport of divalent cations. Membranes developed composed of PPy films deposited on commercially available support materials. To carry out this study, cation exchange membranes based on PPy doped with immobile anions were prepared. Two types of dopant anions known to interact with divalent metal ions were considered, namely 4-sulphonic calix[6]arene (C6S) and carboxylated multiwalled carbon nanotubes (CNT). The transport of ions across membranes containing PPy doped with polystyrene sulphonate (PSS) and PPy doped with para-toluene sulphonate (pTS) was also studied in order to understand the nature of ion transport and permeability across PPy(CNT) and PPy(C6S) membranes. In the course of these studies, membrane characterisation was performed using electrochemical quartz crystal microbalance (EQCM) and scanning electron microscopy (SEM). Permeability of the membranes towards divalent cations was explored using a two compartment transport cell. EQCM results demonstrated that the ion exchange behaviour of polypyrrole is dependent on a number of factors including the type of dopant anion present, the type of ions present in the surrounding medium, the scan rate used during the experiment and the previous history of the polymer film. The morphology of PPy films was found to change when the dopant anion was varied and even when the thickness of the film was altered in some cases. In nearly all cases the permeability of the membranes towards metal ions followed the order K+ > Ca2+ > Mn2+. The one exception was PPy(C6S), for which the permeability followed the order Ca2+ ≥ K+ > Mn2+ > Co2+ > Cr3+. The above permeability sequences show a strong dependence on the size of the metal ions with metal ions having the smallest hydrated radii exhibiting the highest flux. Another factor that affected the permeability towards metal ions was the thickness of the PPy films. Films with the least thickness showed higher metal ion fluxes. Electrochemical control over ion transport across PPy(CNT) membrane was obtained when films composed of the latter were deposited on track-etched Nucleopore® membranes as support material. In contrast, the flux of ions across the same film was concentration gradient dependent when the polymer was deposited on polyvinylidene difluoride membranes as support material. However, electrochemical control over metal ion transport was achieved with a bilayer type of PPy film consisting of PPy(pTS)/PPy(CNT), irrespective of the type of support material. In the course of studying macroscopic charge balance during transport experiments performed using a two compartment transport cell, it was observed that PPy films were non-permselective. A clear correlation between the change in pH in the receiving solution and the ions transported across the membrane was observed. A decrease in solution pH was detected when the polymer membrane acted primarily as an anion exchanger, while an increase in pH occurred when it functioned as a cation exchanger. When there was an approximately equal flux of anions and cations across the polymer membrane, the pH in the receiving solution was in the range 6 - 8. These observations suggest that macroscopic charge balance during the transport of cations and anions across polypyrrole membranes was maintained by introduction of anions (OH-) and cations (H+) produced via electrolysis of water.

The Sedimentology, Ichnology and Hydrogeochemistry of the Late Miocene, Marginal Marine, Upper Pebas and Nauta Formations, Amazonian Foreland Basin, Peru

This thesis includes detailed sedimentological and ichnological studies on two geological units: the Pebas Formation, with a special focus in its informal upper member, and the Nauta Formation. Both formations were deposited during the Miocene in Northeastern Peruvian Amazonia, in the Amazon retroarc foreland basin. The Pebas and Nauta successions mainly consist of non-consolidated, clastic sedimentary deposits arranged into sand- to mud-dominated heterolithic successions, which can be upward-coarsening to upward-fining. Sediments in both the Pebas and Nauta successions range from mud to fine- to medium-grained sand. The main facies observed were 1) mud-dominated horizontal heterolithic couplets; 2) rooted brownish mud; 3) lenticular, mud-draped, cross-stratified sand; 4) mud- to sand-dominated, inclined heterolithic stratification; 5) sand-dominated horizontal heterolithic couplets; and 6) mud-draped, trough cross-stratified sand. Locally, tidal rhythmites were documented. The facies are interpreted as: 1) muddy, shallow, subaqueous flats/shoals; 2) palaeosols; 3) secondary tidal channels or run-off creeks; 4) tidally influenced point bars; 5) shoreface deposits; and 6) subtidal compound dunes. Thalassinoides-dominated Glossifungites ichnofacies, low-diversity expressions of the Skolithos ichnofacies and depauperate suites consisting of elements common to the Cruziana ichnofacies strongly indicate brackish-water conditions. However, continental trace fossil assemblages, with possible elements common to the Scoyenia ichnofacies, have also been identified. In addition to the palaeoenvironmental study, a local hydrogeochemical characterisation of the Pebas and Nauta formations was also conducted. The geochemistry of the groundwaters reflects the characteristics and the soil geochemistry of the geological formations studied. The Pebas formation has low hardness, acid to neutral waters, whereas the upper Pebas has high hardness, acid to neutral waters. In both units, the arsenic content is locally high. The Nauta formation has low hardness acid groundwaters. A regional review of the Pebas and Nauta formations placed the local observations into a continental perspective and suggests that the whole Pebas-Nauta system was a probably shallow (some tens of metres at maximum), brackish- to freshwater, tidally-influenced epicontinental embayment with a probable semi-diurnal to mixed tidal regime and a microtidal range, surrounded by continental environments such as forest floors, lagoons, rivers and their flood plains, and lakes.

Aggression and its Management in Adolescent Forensic Psychiatric Care

The overall goal of this study was to explore and identify good aggression management methods and on that basis to produce recommendations for aggression management in the adolescent forensic setting. The study was conducted in three phases. In Phase I, staff’s (n = 58) perception of adolescent aggressive behaviour and methods to manage it was examined. In Phase II, staff’s (n = 30) perception of treatment settings and treatment interventions available were studied. In Phase III, the effectiveness of an aggression management programme was evaluated. The data were collected during the period 2004-2007. Participants perceived adolescent aggressive behaviour in a similar way and described aggressive behaviour as being a comprehensible phenomenon. Management methods used to control aggressive situations were alike, although the practical solutions varied between the study units, especially regarding coercive methods. Staff members proposed more time and better opportunities to discuss and evaluate the aggression situation in order to improve the methods used. The treatment settings were similar in studied forensic units and interventions were primarily focused on psychological aspects, including management of aggressive behavior. A comprehensive aggression management programme proved to be effective in decreasing incidents of violence. The use of coercive methods in aggression situations decreased and injuries to the staff became less frequent. If staff members intend to apply high quality management methods in aggression situations they have to share a consistent understanding of aggressive behaviour and need to be aware of the various methods available. In addition, they should learn more about assessment methods in order to improve aggression management. International comparison of aggression, methods for managing it and service provision creates a starting point for developing equal care provision and realization within and between European countries.

Exploration and Design of Power-Efficient Networked Many-Core Systems

Multiprocessing is a promising solution to meet the requirements of near future applications. To get full benefit from parallel processing, a manycore system needs efficient, on-chip communication architecture. Networkon- Chip (NoC) is a general purpose communication concept that offers highthroughput, reduced power consumption, and keeps complexity in check by a regular composition of basic building blocks. This thesis presents power efficient communication approaches for networked many-core systems. We address a range of issues being important for designing power-efficient manycore systems at two different levels: the network-level and the router-level. From the network-level point of view, exploiting state-of-the-art concepts such as Globally Asynchronous Locally Synchronous (GALS), Voltage/ Frequency Island (VFI), and 3D Networks-on-Chip approaches may be a solution to the excessive power consumption demanded by today’s and future many-core systems. To this end, a low-cost 3D NoC architecture, based on high-speed GALS-based vertical channels, is proposed to mitigate high peak temperatures, power densities, and area footprints of vertical interconnects in 3D ICs. To further exploit the beneficial feature of a negligible inter-layer distance of 3D ICs, we propose a novel hybridization scheme for inter-layer communication. In addition, an efficient adaptive routing algorithm is presented which enables congestion-aware and reliable communication for the hybridized NoC architecture. An integrated monitoring and management platform on top of this architecture is also developed in order to implement more scalable power optimization techniques. From the router-level perspective, four design styles for implementing power-efficient reconfigurable interfaces in VFI-based NoC systems are proposed. To enhance the utilization of virtual channel buffers and to manage their power consumption, a partial virtual channel sharing method for NoC routers is devised and implemented. Extensive experiments with synthetic and real benchmarks show significant power savings and mitigated hotspots with similar performance compared to latest NoC architectures. The thesis concludes that careful codesigned elements from different network levels enable considerable power savings for many-core systems.

Maailmalle yhtenä, takaisin toisena? Suomalaisten ekspatriaattiperheiden lapset kulttuurisissa siirtymissä

Tutkimuksessa tarkastellaan vanhemman globaalin työn vuoksi tapahtuvaa perheen ulkomaille muuttoa ja paluumuuttoa lapsen kulttuurisina siirtyminä. Tutkittavista lapsista käytetään käsitettä ekspatriaattiperheen lapset. Ekspatriaatti määrittyy väliaikaisesti ulkomailla työskenteleväksi työntekijäksi, joka voi olla ulkomailla joko työnantajansa lähettämänä tai itsenäisesti työpaikkansa järjestäneenä. Ekspatriaattiutta ei rajata perinteisen ekspatriaattitutkimuksen tapaan ainoastaan yritysmaailmaan, vaan siihen sisällytetään myös muiden alojen työntekijät kuten tutkijat. Tutkimus tarkastelee siten makrotason ilmiöiden – globaalin työelämän ja kansainvälisen liikkuvuuden – seurauksia mikrotasolla, lapsen elämässä. Tutkimuksen aineisto kerättiin kahdeksan suuren suomalaiskaupungin (Espoo, Tampere, Vantaa, Turku, Oulu, Lahti, Kuopio ja Jyväskylä) peruskoulujen kautta. Aineisto koostuu vanhemmilta kerätystä sähköisestä kyselyaineistosta (N = 202 perhettä, 333 lasta) sekä lapsilta kerätystä haastatteluaineistosta (N = 8). Tutkimuksessa käytettiin erityisesti kahta teoreettista lähestymistapaa: perhetutkimuksellista näkökulmaa ja siinä tarkemmin perhesysteemistä teoriaa sekä lapsuudentutkimuksellista näkökulmaa. Tutkimuksessa selvitettiin ekspatriaattiperheiden voimavaroja, jotka muodostavat lasten kulttuuristen siirtymien keskeisen kontekstin. Tutkimuksen tehtävänä oli kuvailla lasten sopeutumista siirtymiin sekä löytää sille mahdollisia selityksiä. Sopeutumisen käsite kattaa psykologisen ja sosiokulttuurisen sopeutumisen sekä kulttuurisen identiteetin. Lisäksi tutkimustehtävänä oli ymmärtää lasten kokemusten rakentumista ulkomaille muuton ja paluumuuton siirtymissä. Siirtymäkokemukset nähdään sopeutumisen ulottuvuuksia vastaten tunteina, toimintana ja identiteettinä. Keskiluokkaisilla ekspatriaattiperheillä oli runsaasti voimavaroja. Perheiden sisäiset voimavarat olivat vahvat, vaikkakin vanhemmuudessa oli havaittavissa epätasapainoisen lapsi-vanhempisuhteen merkkejä. Ekspatriaattiperheet olivat kulttuurisissa siirtymissä dynaamisessa muutoksessa. Tulosten perusteella vanhempien tulisi ulkomaille muuton ja paluumuuton siirtymissä keskittyä takaamaan lasten jatkuvuuden kokemuksia sekä tukemaan lasten emotionaalista hyvinvointia. Perheiden ulkopuolisissa voimavaroissa epävirallisen sosiaalisen tuen merkitys oli tärkeä. Virallinen tuki, työn ja koulun tuki, oli ulkomailla asuttaessa hyödyllisempää kuin paluumuuton jälkeen. Kansainvälisten koulujen sijaan lapset kävivät pääosin ”tavallista” koulua. Vanhemmilta kerätyn aineiston perusteella lasten ulkomaille muuttoon ja paluumuuttoon sopeutumisesta piirtyi erittäin myönteinen kuva. Lapsen sopeutumiseen heijastuivat erityisesti perheeseen liittyvät asiat. Perhe oli lasten kulttuuristen siirtymien keskeisin konteksti ja myös tärkein tukija. Ulkomaille muutto näyttäytyi paluumuuttoa vaikeampana siirtymänä ainoastaan sosiaaliskielellisten vaikeuksien näkökulmasta. Paluumuuton haasteellisuus suhteessa ulkomaille muuttoon tuli esiin tuloksissa. Lasten haastatteluaineisto toi vanhempien myönteisen käsityksen rinnalle myös muita sävyjä. Lasten kokemuksia rakensi muun muassa ikävän tunne. Lasten identiteetit näyttäytyivät lapsilta kerätyn aineiston valossa dynaamisina ja tilanteisina. Paluumuuton jälkeen osalla lapsista oli kulttuurienvälinen identiteetti. Lasten kulttuurienvälisyys on suomalaisessa kontekstissa piilossa: lapset nähdään ainoastaan suomalaisina. Lasten identiteettien kulttuurienvälisyys tulisi saada näkyviin kodin ulkopuolella. Koulukontekstissa tätä tukisi paluuoppilaskäsitteen uudelleen käyttöönotto, joka liittäisi nämä kulttuurienväliset lapset osaksi kulttuurienvälisyyskasvatusta.

L'Univers

1895/12/14 (Numéro 10198).

La Jeunesse illustrée

1930/12/14 (N1419).

La Jeunesse illustrée

1924/12/14 (N1106).

La Jeunesse illustrée

1919/12/14 (N848).

On Innovative Search: the use of internal and external sources of innovation among Finnish innovators

This dissertation explores the use of internal and external sources of knowledge in modern innovation processes. It builds on a framework that combines theories such as a behavioural theory of the firm, the evolutionary theory of economic change, and modern approaches to strategic management. It follows the recent increase in innovation research focusing on the firm-level examination of innovative activities instead of traditional industry-level determinants. The innovation process is seen as a problem- and slack- driven search process, which can take several directions in terms of organizational boundaries in the pursuit of new knowledge and other resources. It thus draws on recent models of technological change, according to which firms nowadays should build their innovative activities on both internal and external sources of innovation rather than relying solely on internal resources. Four different research questions are addressed, all of which are empirically investigated via a rich dataset covering Finnish innovators collected by Statistics Finland. Firstly, the study examines how the nature of problems shapes the direction of any search for new knowledge. In general it demonstrates that the nature of the problem does affect the direction of the search, although under resource constraints firms tend to use external rather than internal sources of knowledge. At the same time, it shows that those firms that are constrained in terms of finance seem to search both internally and externally. Secondly, the dissertation investigates the relationships between different kinds of internal and external sources of knowledge in an attempt to find out where firms should direct their search in order to exploit the potential of a distributed innovation process. The concept of complementarities is applied in this context. The third research question concerns how the use of external knowledge sources – openness to external knowledge – influences the financial performance of firms. Given the many advantages of openness presented in the current literature, the focus is on how it shapes profitability. The results reveal a curvilinear relationship between profitability and openness (taking an inverted U-shape), the implication being that it pays to be open up to a certain point, but being too open to external sources may be detrimental to financial performance. Finally, the dissertation addresses some challenges in CISbased innovation research that have received relatively little attention in prior studies. The general aim is to underline the fact that comprehensive understanding of the complex process of technological change requires the constant development of methodological approaches (in terms of data and measures, for example). All the empirical analyses included in the dissertation are based on the Finnish CIS (Finnish Innovation Survey 1998-2000).