Aerodynamical instability of web

Diplomityön tavoitteena oli tutkia miten ilman turbulenttisuus vaikuttaa tasaisesti liikkuvan rainan tilaan. Yhtenä sovelluskohteena teollisuudessa voidaan mainita esimerkiksi leiju-kuivain. Tiedetään, että konenopeuksien kasvu ja siitä johtuva ilmavirran nopeuden kasvu aiheuttaa voimavaikutuksia rainaan ja voi aiheuttaa lepatusta. Lepatus johtaa dynaamiseen epästabiilisuuteen, joka voidaan havaita, kun lineaarinen systeemi tulee epävakaaksi ja joh-taa epälineaariseen, rajoitettuun värähtelyyn. Lepatus huonontaa tuotteiden laatua ja voi johtaa ratakatkoihin. Työssä on esitetty tietoa ilman ja rainan vuorovaikutuksesta, jota hyödyntämällä voidaan kehittää yksinkertaistettu malli, jonka avulla liikkuvaa rainaa voidaan simuloida kuivaimes-sa. Kaasufaasin virtausyhtälöt on ratkaistu eri turbulenttimalleja käyttäen. Myös viskoelas-tisen rainan muodonmuutosta on tarkasteltu. Koska rainalle ei ole kirjallisuudesta saatavilla tarkkoja fysikaalisia ja mekaanisia arvoja, näitä ominaisuuksia testattiin eri arvoilla, jotta rainan käyttäytymistä jännityksen alaisena voidaan tarkastella. Näiden ominaisuuksien tun-teminen on ensiarvoisen tärkeää määritettäessä rainan aeroviskoelastista käyttäytymistä. Virtaussimulointi on kallista ja aikaa vievää. Tämä tarkoittaa uusien tutkimusmenetelmien omaksumista. Tässä työssä vaihtoehtoisena lähestymistapana on esitetty yksinkertaistettu malli, joka sisältää ilman ja rainan vuorovaikutusta kuvaavat ominaisuudet. Mallin avulla saadaan tietoa epälineaarisuuden ja turbulenssin vaikutuksesta sekä monimutkaisesta yh-teydestä stabiilisuuden ja ulkoisesti aikaansaadun värähtelyn sekä itse aiheutetun värähtelyn välillä. Työn lopussa on esitetty havainnollinen esimerkki, jolla voidaan kuvata olosuhteita, jossa rainan tasainen liike muuttuu epävakaaksi. Kun turbulenttisuudesta johtuva painevaih-telu ylittää tietyn rajan, rainan värähtely kasvaa muuttuen satunnaisesta järjestäytyneeksi. Saaduttulokset osoittavat, että turbulenttisuudella on suuri vaikutus eikä sitä voi jättää huomioimatta. Myös rainan viskoelastiset ominaisuudet tulee huomioida, jotta rainan käyt-täytymistä voidaan kuvata tarkasti.

Sellu ja paperiteollisuuden jätevesien tertiäärikäsittelyn kemikaloinnin optimointi

Kuluneen vuosikymmenen aikana metsäteollisuuden päästöt ympäristöön ovat pienentyneet huomattavasti tuotantomäärien kasvustahuolimatta. Lainsäädännön myötä lupa-arvot tiukentuvat edelleen joten olemassa olevia puhdistus prosesseja on parannettava ja niiden rinnalle on kehitettävä uusia, yhä tehokkaampia menetelmiä. Aquaflow Oy suunnittelee jäteveden puhdistamoja sellu- ja paperiteollisuuteen. Kilpailun kiristyessä kilpailuetua haetaan jatkuvan kehittymisen kautta. Yhä useammilla jäteveden puhdistamoilla tarvitaan teriäärikäsittely biohajoamattoman aineksen poistamiseen. Tertiäärikäsittely on käyttökustannuksiltaan kallis kemikaali kulutuksensa vuoksi. Tässä työssä pyrittiin optimoimaan tertiääriprosessin kemikaalien syöttöä. Lisäksi selvitettiin millaisissa oloissa keskeiset saostus ja flokkaus prosessit toimivatparhaiten, sekä mitkä tekijät vaikuttavat merkittävästi jäteveden kemiallisen käsittelyn tulokseen. Saatujen tulosten perusteella kemikaalien sekoituksen tehostuksen seurauksena kemikaali määriä voidaan pienentää, samalla puhdistustulos paranee ja jäännöskemikaalien määrä pienenee. pH:n säätö on olennainen osa prosessin toiminnan kannalta, jos pH ei ole kemikaalien toiminta alueella ei puhdistusta tapahdu ja kemikaalit kulkeutuvat luontoon. Tertiäärikäsittelyyn tulevan jäteveden online seurannan avulla juuri oikea kemikaaliannos olisihelpompaa määrittää kuin päivän viiveellä tulevien laboratorio analyysien perusteella ja yli-/ali annostukselta vältyttäisiin

Simulation of Boundary Layers and Heat Transfer in the Entrance Region of Pipes

The study of fluid flow in pipes is one of the main topic of interest for engineers in industries. In this thesis, an effort is made to study the boundary layers formed near the wall of the pipe and how it behaves as a resistance to heat transfer. Before few decades, the scientists used to derive the analytical and empirical results by hand as there were limited means available to solve the complex fluid flow phenomena. Due to the increase in technology, now it has been practically possible to understand and analyze the actual fluid flow in any type of geometry. Several methodologies have been used in the past to analyze the boundary layer equations and to derive the expression for heat transfer. An integral relation approach is used for the analytical solution of the boundary layer equations and is compared with the FLUENT simulations for the laminar case. Law of the wall approach is used to derive the empirical correlation between dimensionless numbers and is then compared with the results from FLUENT for the turbulent case. In this thesis, different approaches like analytical, empirical and numerical are compared for the same set of fluid flow equations.

The Paleozoic magmatic history of the Maggia and Sambuco nappes, Lower Penninic, Central Lepontine Alps

Résumé : Les corps magmatiques sont des indicateurs essentiels dans toute reconstitution paléogéographique et/ou géodynamique d'un cycle orogénique, en particulier en contexte polycyclique, où la plupart des autres indices ont été oblitérés. Ils sont aisément datables et leurs caractéristiques géochimiques permettent de contraindre leur contexte tectonique de mise en place. Cette approche a été appliquée aux socles pré-mésozoïques des nappes penniques inférieures de Sambuco et de la Maggia, dans les Alpes centrales lepontines. Plusieurs événements magmatiques ont été identifiés dans le socle de Sambuco et datés par la méthode U-Pb sur zircon couplée à la technique LA-ICPMS. La suite calco-alcaline mafique rubanée de Scheggia est datée du Cambrien inférieur à 540-530 Ma ; le métagranite alumineux oeillé de Sasso Nero a un âge de 480-470 Ma, tout comme bien d'autres «older orthogneisses» des socles alpins. Il contient des zircons hérités d'âge panafricain à 630-610 Ma, indicateur d'une affiliation gondwanienne de ces terrains. Le pluton calco-alcalin du Matorello est daté à environ 300-310 Ma, et les filons lamprophyriques qu'il abrite à 300 Ma. La granodiorite de Cocco et le leucogranite de Ruscada, tous deux intrudés dans le socle de la nappe adjacente de la Maggia, ont des âges similaires à celui du Matorello. Ceci ajouté aux similitudes magmatiques observées entre Cocco et Matorello suggère une proximité paléogéographique des deux nappes au Permien-Carbonifère. Or ces dernières sont actuellement considérées appartenir à deux domaines paléogéographiques mésozoïques distincts : helvétique pour Sambuco et briançonnais pour Maggia, séparés par un bassin océanique. Si tel fut le cas, aucun mouvement décrochant ne doit avoir décalé les marges continentales de l'océan, retrouvées en parfaite coïncidence lors de sa fermeture. Le Matorello est un pluton recristallisé en faciès amphibolite et plissé par cinq phases successives de déformation non-coaxiales, qui ont conduit à son renversement complet, attesté par des indicateurs de paléogravité. Il préserve de spectaculaires phénomènes de coexistence liquide de magmas (essaims d'enclaves et Bills composites). Ce pluton était originellement tabulaire, construit par l'accumulation de multiples injections de magma en feuillets d'épaisseur métrique à décamétrique. Suivant le rythme de mise en place, les injections successives ont rapidement cristallisé avec des contours nets et bien définis (Bills composites) ou se sont mélangées avec les précédentes pour former une couche non consolidée de plusieurs dizaines de mètres d'épaisseur (granodiorite principale). Les injections individuelles sont délimitées par de subtils contrastes en granulométrie, proportions modales ou ségrégation de minéraux (schlieren), ou par des phénomènes d'érosion le long des surfaces de contact. Deux couches métriques à contour sinueux consistent en une accumulation compacte d'enclaves mafiques arrondies dans une matrice granodioritique fine. Le granoclassement des enclaves, la présence de figures de charge et de phénomènes érosifs en base de couche, ainsi que des schlieren de biotite entrecroisés évoquent l'injection de coulées de magma chargé d'enclaves et de faible viscosité en régime hydrodynamique turbulent dans un encaissant granodioritique encore largement liquide. La nature hybride des roches implique une chambre magmatique sous-jacente, en cours de différenciation et périodiquement réalimentée. Les magmas sont des liquides mafiques dérivés du manteau et des liquides anatectiques d'origine crustale, comme l'indique la gamme mesurée des rapports isotopiques initiaux du Sr (0.704 à 0.709) et des valeurs epsilon Nd (-2.1 à -4.7). Ces données montrent également que la contribution crustale est dominante, en accord avec les isotopes du plomb. Les phénomènes d'hybridation ont vraisemblablement eu lieu en base de croûte et dans la chambre magmatique sous-jacente au laccolite du Matorello. Les indicateurs de paléogravité du Matorello contribuent accessoirement à la compréhension de l'architecture actuelle de la nappe de Sambuco. Des plis isoclinaux à surface axiale verticale peuvent être mis en évidence par le contact entre les faciès dioritique et granodioritique. L'antiforme dont le Matorello forme le coeur est un synclinal, ce qui le positionne dans le Flanc inverse du grand pli couché que forme la nappe de Sambuco. Par ailleurs, des blocs de gneiss retrouvés dans le wildflysch sommital de la couverture de la nappe d'Antigorio ont été affiliés dans cette étude au pluton du Matorello. Ceci implique que le front de la nappe de Sambuco chevauchait déjà la partie est du bassin d'Antigorio au moment de sa fermeture. Par conséquent, ce n'est qu'en position externe que la nappe du Lebendun chevauche directement la nappe d'Antigorio. Abstract Magmatic bodies are important markers in paleo-geographic or geodynamic reconstructions of orogenic cycles, even more so in the case of polycyclic events where many of the other markers have been overwritten or destroyed. Plutons are relatively easy to date and their geochemical properties help constrain the tectonic context in which they were emplaced. This study focuses on the pre-mesozoic basement in the Sambuco and Maggia lower Penninic nappes located in the central Lepontine domain of the Alps. A number of magmatic events have been identified in the Sambuco basement. These events were dated using LA-ICPMS U/Pb on zircon grains. The mafic calc-alkaline banded Scheggia suite is dated as lower Cambrian, 540-530 Ma. The Al-rich Sasso-Nero lenticular gneiss is 480-470 Ma old (similarly to many older orfhogneisses of the Alpine basement) and contains 630-610 Ma old pan-African inherited zircons that illustrate the Gondwanian origin of these terranes.The calc-alkaline Matorello pluton is dated as 310-300 Ma whereas the lamprophyric bodies it contains are of 300 Ma. The Cocco granodiorite and the Ruscada leucogranite both intrude the basement of the adjacent Maggia nappe and are of similar ages to the Matorello. The ages as well as the geochemical similarities between the Cocco, Rucada and Matorello plutons suggest their paleo-geographic proximity at the Permian-Carboniferous boundary. However, these nappes are currently considered as belonging to two different Mesozoic paleo-geographic domains. Indeed, the Sambuco is considered as Helvetic whereas the Maggia is said to be Briançonnais, both separated by an oceanic basin. If this is the case, then it is essential that nostrike-slip movement has misaligned both continental margins since these coincide perfectly now that the oceanic domain closed. The Matorello pluton was originally a tabular intrusion, built up by the accumulation of multiple, several meter-thick, subhorizontal sheet-like injections of magma. Depending on their emplacement rate, the successive magma injections either solidified rapidly with sharp and rather well-defined boundaries (like the composite sills) or mingled with previous injections generating a thick molten layer up to several tens to hundred meters thick, like in the main granodioritic facies. These coalesced injections are hardly distinguishable, however subtle contrasts in granulometry, mineral modal proportions or mineral sorting (cross-bedded biotite-rich schlieren), as well as erosional features and/or crystal entrapment along contact surfaces allow to distinguish between the different injections. Two exceptional meter-thick layers display sinuous boundaries with the host granodiorite and consist of a densely packed accumulation of mafic enclaves in a granodioritic matrix. Gravitational sorting of the enclaves with load cast features at the base of the layers and sinuous biotite schlieren point to injection of low viscosity turbulent composite magma flows in the still largely molten granodiorite host. The hybrid nature of these rocks implies the existence of á periodically replenished and differentiated underlying magma chamber. Magmas are mafic liquids derived from the mantle and anatectic liquids of crustal origin, as shown by the (87Sr/86Sr), and epsilon Nd values (0.704-0.709 and -2.1 to -4.7 respectively. These data show that the crustal contribution is important, as confirmed by the Pb isotopes. The hybridisation processes seem to have occurred in the lower crust in magma chambers underlying the Matorello laccolith. The paleo-gravity markers in the Matorello help understand the architecture of the Sambuco nappe. Isoclinal folds with a vertical axial plane can be seen at the contact between dioritic and granodioritic facies. The antiform structure of which the Matorello is the heart is in fact a syncline. This places it in the inverse flanc of the large recumbent fold that constitutes the Sambuco nappe. The gneiss blocs found in the summital wildflysh cover of the Antigorio nappe have been linked to the Matorello pluton. This means that the front of the Sambuco nappe already overlapped the Antigorio basin when it closed. This implies that the Lebendun nappe can only overlap the Antigorio nappe in it's external position. Résumé grand public La chaîne alpine est la conséquence de la collision tertiaire entre deux masses continentales, l'Europe au nord et la péninsule apulienne africaine au sud, originellement séparées par l'océan mésozoïque téthysien. Cette collision a fermé un espace large de plusieurs centaines de km avec pour résultat l'écaillage de la croûte terrestre en unités tectoniques de dimensions variables, qui se sont empilées, imbriquées, éventuellement replissées en nappes de géométrie complexe. Cet amoncellement de 40 km d'épaisseur a vu sa température et sa pression lithostatique internes augmenter jusqu'à des valeurs de l'ordre de 680 °C et 6000 bars, induisant une recristallisation métamorphique des roches. L'un des objectifs de la géologie alpine est de reconstituer la géographie de la région aux temps mésozoïques de l'océan téthysien, en d'autres termes, de replacer chacune des unités tectoniques identifiées au sein de l'empilement alpin dans sa position originelle. Le défi est de taille et peut être comparé à celui de la reconstitution d'un vaste puzzle, dont certaines pièces seraient endommagées au niveau de leur contour ou leurs couleurs (métamorphisme), dissimulées par d'autres (enfouissement), voire tombées de la table de jeu (subduction, échappement latéral). Plusieurs approches ont été mises en oeuvre au cours du siècle écoulé. On citera en particulier la stratigraphie, la tectonique et le paléomagnétisme. Dans ce travail, nous avons essentiellement utilisé des techniques de datation isotopique absolue des roches (U/Pb sur zircon) qui, sur la base des connaissances acquises par l'ensemble des autres disciplines géologiques, nous ont permis de mieux contraindre ta paléogéographie mésozoïque du domaine «pennique inférieur » des Alpes centrales lépontines. Et au-delà? Nous savons tous que la disposition des continents à la surface de la Terre évolue constamment. Il est donc tentant d'essayer de remonter plus loin encore dans le temps et de reconstituer la physionomie de la marge sud européenne, tout au moins certains éléments de son histoire, au cours de l'ère paléozoïque. Les traces de ces événements très anciens sont naturellement ténues et dans ce contexte, les techniques de datation mentionnées ci-dessus deviennent les outils les plus performants. Ainsi, des datations u/Pb sur zircon nous ont permis de recenser plusieurs intrusions magmatiques, attribuées à quatre événements orogéniques anté-alpins. Des âges néoprotérozoïques (630-610 millions d'années ou Ma), cambrien inférieur (540-530 Ma), ordovicien inférieur (480-470 Ma) et carbonifère supérieur-permien inférieur (310-285 Ma) ont été obtenus dans le socle de la nappe de Sambuco. Des âges similaires à 300 Ma ont été obtenus dans la nappe voisine de la Maggia, qui permettent de relier ces deux unités. Aujourd'hui côte à côte, ces deux nappes devaient également se trouver proches l'une de l'autre il y a 300 Ma, lors de l'extension post-varisque. Les structures magmatiques spectaculaires préservées dans le pluton du Matorello (300 Ma) contraignent la géométrie actuelle de la nappe de Sambuco dans laquelle l'intrusion s'est mise en place. La forme originelle du pluton, aujourd'hui retourné et replissé plusieurs fois, s'avère être tabulaire, faite d'intrusions de faible épaisseur (1-300 m) s'étalant en forme de disque (30m à 2 km de diamètre). Les injections successives de magma se sont accumulées sous un toit dioritique précoce; elles sont issues, par le refais de fractures, d'une chambre magmatique plus profonde, périodiquement réalimentée par des magmas calco-alcalins d'origine mantellique contaminés parla croûte continentale profonde (εNd = -2.1 à -4.7). Des accumulations d'enclaves magmatiques arrondies et granoclassées dans des paléo-chenaux à fond érosif témoignent de conditions de mise en place hydrodynamiques à haute énergie. Ces enclaves sont emmenées de la chambre magmatique sous-jacente à la faveur d'épisodes de fracturation hydraulique liés à l'injection de magmas matelliques chauds dans des liquides différenciés riches en eau. Cette hypothèse est étayée par l'existence de filons composites. Une paléohorizontale a pu être déduite au sein du pluton, indiquant que cette partie de la nappe de Sambuco est verticalisée et isoclinalement replissée par la déformation alpine. Finalement, des blocs érodés du socle Sambuco ont été retrouvés dans le wildflysch sommital de la couverture sédimentaire mésozoïque de la nappe d'Antigorio sous-jacente. Ceci suggère que les blocs ont été fournis parle front de la nappe de Sambuco en train de chevaucher sur la nappe d'Antigorio au moment de la fermeture du bassin sédimentaire de cette dernière.

Exploring the strategic impact of technological change - Studies on the role of Internet in magazine publishing

Over the past few decades, turbulent change has characterized the situation in the media industry. It has been noted that digitalization and new media are strongly influencing the industry: it is changing the existing market dynamics and requires new strategies. Prior research on the impact of digitalization and the Internet has emphasized news-focused media such as newspaper publishing and broadcasting, yet magazine publishing is very seldom the focus of the research. This study examines how the Internetimpacts magazine publishing. The work presents a multi-level analysis on the role and impact of the Internet on magazine products, companies and industry. The study is founded on strategic management, technology management and media economics literature. This study consists of two parts. The first part introduces the research topic and discusses the overall results of the study. The second part comprises five research publications. Qualitative research methods are used throughout. The results of the study indicate that the Internet has not had a disruptive effect on magazine publishing, and that its strategic implications could rather be considered complementary to the print magazine and the business as a whole. It seems that the co-specialized assets, together with market-related competencies and unchanged core competence have protected established firms from the disruptive effect of the new technology in magazine publishing. In addition, it seems that the Internet offers a valuable possibility to build and nourish customer relationships. The study contributes tomedia management and economics research by moving from product- or industry-level investigations towards a strategic-management perspective.

Fouling, prevention of fouling, and clearing in filtration

In this thesis fouling of conventional filter fabrics and membranes was studied. In the beginning of the thesis fouling and how it can be measured and predicted is reviewed. Information on different methods on how fouling canbe decreased or cleaned away is also given. The experimental part is divided into two sections; fabric filtration and membrane filtration. Fouling of the filter fabrics was studied with silica or cupper slurries and fouling of the membranes was studied with pulp and paper mill waters. The fouled filter materials were characterised according to many different methods. The most useful way to observe fouling is to measure the changes in the permeate flux. Fouling can also be seen visually e.g. with scanning electron microscopy. Consequently, also the reason for the fouling in question might be found. Different filtration characteristics affect fouling e.g. as the filtration pressure was increased it did not have much influence on the permeate flux, but the pressure caused the membrane to get fouled faster. Also, an increase of shear rate on the membrane surface decreased fouling. Different pretreatment methods for the effluent were tested in membrane filtration to decrease fouling. The tested methods; biological treatment, ozonation, enzymatic treatment and flocculation, did not have a clear influence on the fouling of the membrane, but e.g. a biological treatment combined with ultrafiltration made the tested groundwood mill circulation water purer than ultrafiltration alone.

R&D Performance Analysis: Case Studies on the Challenges and Promotion of the Evaluation and Measurement of R&D

Due to the intense international competition, demanding, and sophisticated customers, and diverse transforming technological change, organizations need to renew their products and services by allocating resources on research and development (R&D). Managing R&D is complex, but vital for many organizations to survive in the dynamic, turbulent environment. Thus, the increased interest among decision-makers towards finding the right performance measures for R&D is understandable. The measures or evaluation methods of R&D performance can be utilized for multiple purposes; for strategic control, for justifying the existence of R&D, for providing information and improving activities, as well as for the purposes of motivating and benchmarking. The earlier research in the field of R&D performance analysis has generally focused on either the activities and considerable factors and dimensions - e.g. strategic perspectives, purposes of measurement, levels of analysis, types of R&D or phases of R&D process - prior to the selection of R&Dperformance measures, or on proposed principles or actual implementation of theselection or design processes of R&D performance measures or measurement systems. This study aims at integrating the consideration of essential factors anddimensions of R&D performance analysis to developed selection processes of R&D measures, which have been applied in real-world organizations. The earlier models for corporate performance measurement that can be found in the literature, are to some extent adaptable also to the development of measurement systemsand selecting the measures in R&D activities. However, it is necessary to emphasize the special aspects related to the measurement of R&D performance in a way that make the development of new approaches for especially R&D performance measure selection necessary: First, the special characteristics of R&D - such as the long time lag between the inputs and outcomes, as well as the overall complexity and difficult coordination of activities - influence the R&D performance analysis problems, such as the need for more systematic, objective, balanced and multi-dimensional approaches for R&D measure selection, as well as the incompatibility of R&D measurement systems to other corporate measurement systems and vice versa. Secondly, the above-mentioned characteristics and challenges bring forth the significance of the influencing factors and dimensions that need to be recognized in order to derive the selection criteria for measures and choose the right R&D metrics, which is the most crucial step in the measurement system development process. The main purpose of this study is to support the management and control of the research and development activities of organizations by increasing the understanding of R&D performance analysis, clarifying the main factors related to the selection of R&D measures and by providing novel types of approaches and methods for systematizing the whole strategy- and business-based selection and development process of R&D indicators.The final aim of the research is to support the management in their decision making of R&D with suitable, systematically chosen measures or evaluation methods of R&D performance. Thus, the emphasis in most sub-areas of the present research has been on the promotion of the selection and development process of R&D indicators with the help of the different tools and decision support systems, i.e. the research has normative features through providing guidelines by novel types of approaches. The gathering of data and conducting case studies in metal and electronic industry companies, in the information and communications technology (ICT) sector, and in non-profit organizations helped us to formulate a comprehensive picture of the main challenges of R&D performance analysis in different organizations, which is essential, as recognition of the most importantproblem areas is a very crucial element in the constructive research approach utilized in this study. Multiple practical benefits regarding the defined problemareas could be found in the various constructed approaches presented in this dissertation: 1) the selection of R&D measures became more systematic when compared to the empirical analysis, as it was common that there were no systematic approaches utilized in the studied organizations earlier; 2) the evaluation methods or measures of R&D chosen with the help of the developed approaches can be more directly utilized in the decision-making, because of the thorough consideration of the purpose of measurement, as well as other dimensions of measurement; 3) more balance to the set of R&D measures was desired and gained throughthe holistic approaches to the selection processes; and 4) more objectivity wasgained through organizing the selection processes, as the earlier systems were considered subjective in many organizations. Scientifically, this dissertation aims to make a contribution to the present body of knowledge of R&D performance analysis by facilitating dealing with the versatility and challenges of R&D performance analysis, as well as the factors and dimensions influencing the selection of R&D performance measures, and by integrating these aspects to the developed novel types of approaches, methods and tools in the selection processes of R&D measures, applied in real-world organizations. In the whole research, facilitation of dealing with the versatility and challenges in R&D performance analysis, as well as the factors and dimensions influencing the R&D performance measure selection are strongly integrated with the constructed approaches. Thus, the research meets the above-mentioned purposes and objectives of the dissertation from the scientific as well as from the practical point of view.

Theoretical Analysis and Simulations of Vertically Vibrated Granular Materials

The dynamical properties ofshaken granular materials are important in many industrial applications where the shaking is used to mix, segregate and transport them. In this work asystematic, large scale simulation study has been performed to investigate the rheology of dense granular media, in the presence of gas, in a three dimensional vertical cylinder filled with glass balls. The base wall of the cylinder is subjected to sinusoidal oscillation in the vertical direction. The viscoelastic behavior of glass balls during a collision, have been studied experimentally using a modified Newton's Cradle device. By analyzing the results of the measurements, using numerical model based on finite element method, the viscous damping coefficient was determinedfor the glass balls. To obtain detailed information about the interparticle interactions in a shaker, a simplified model for collision between particles of a granular material was proposed. In order to simulate the flow of surrounding gas, a formulation of the equations for fluid flow in a porous medium including particle forces was proposed. These equations are solved with Large Eddy Simulation (LES) technique using a subgrid-model originally proposed for compressible turbulent flows. For a pentagonal prism-shaped container under vertical vibrations, the results show that oscillon type structures were formed. Oscillons are highly localized particle-like excitations of the granular layer. This self-sustaining state was named by analogy with its closest large-scale analogy, the soliton, which was first documented by J.S. Russell in 1834. The results which has been reportedbyBordbar and Zamankhan(2005b)also show that slightly revised fluctuation-dissipation theorem might apply to shaken sand, which appears to be asystem far from equilibrium and could exhibit strong spatial and temporal variations in quantities such as density and local particle velocity. In this light, hydrodynamic type continuum equations were presented for describing the deformation and flow of dense gas-particle mixtures. The constitutive equation used for the stress tensor provides an effective viscosity with a liquid-like character at low shear rates and a gaseous-like behavior at high shear rates. The numerical solutions were obtained for the aforementioned hydrodynamic equations for predicting the flow dynamics ofdense mixture of gas and particles in vertical cylindrical containers. For a heptagonal prism shaped container under vertical vibrations, the model results were found to predict bubbling behavior analogous to those observed experimentally. This bubbling behavior may be explained by the unusual gas pressure distribution found in the bed. In addition, oscillon type structures were found to be formed using a vertically vibrated, pentagonal prism shaped container in agreement with computer simulation results. These observations suggest that the pressure distribution plays a key rolein deformation and flow of dense mixtures of gas and particles under vertical vibrations. The present models provide greater insight toward the explanation of poorly understood hydrodynamic phenomena in the field of granular flows and dense gas-particle mixtures. The models can be generalized to investigate the granular material-container wall interactions which would be an issue of high interests in the industrial applications. By following this approach ideal processing conditions and powder transport can be created in industrial systems.

Modeling and measuring organizational renewal capability

Globalization and new information technologies mean that organizations have to face world-wide competition in rapidly transforming, unpredictable environments, and thus the ability to constantly generate novel and improved products, services and processes has become quintessential for organizational success. Performance in turbulent environments is, above all, influenced by the organization's capability for renewal. Renewal capability consists of the ability of the organization to replicate, adapt, develop and change its assets, capabilities and strategies. An organization with a high renewal capability can sustain its current success factors while at the same time building new strengths for the future. This capability does not only mean that the organization is able to respond to today's challenges and to keep up with the changes in its environment, but also that it can actas a forerunner by creating innovations, both at the tactical and strategic levels of operation and thereby change the rules of the market. However, even though it is widely agreed that the dynamic capability for continuous learning, development and renewal is a major source of competitive advantage, there is no widely shared view on how organizational renewal capability should be defined, and the field is characterized by a plethora of concepts and definitions. Furthermore,there is a lack of methods for systematically assessing organizational renewal capability. The dissertation aims to bridge these gaps in the existing research by constructing an integrative theoretical framework for organizational renewal capability and by presenting a method for modeling and measuring this capability. The viability of the measurement tool is demonstrated in several contexts, andthe framework is also applied to assess renewal in inter-organizational networks. In this dissertation, organizational renewal capability is examined by drawing on three complimentary theoretical perspectives: knowledge management, strategic management and intellectual capital. The knowledge management perspective considers knowledge as inherently social and activity-based, and focuses on the organizational processes associated with its application and development. Within this framework, organizational renewal capability is understood as the capacity for flexible knowledge integration and creation. The strategic management perspective, on the other hand, approaches knowledge in organizations from the standpoint of its implications for the creation of competitive advantage. In this approach, organizational renewal is framed as the dynamic capability of firms. The intellectual capital perspective is focused on exploring how intangible assets can be measured, reported and communicated. From this vantage point, renewal capability is comprehended as the dynamic dimension of intellectual capital, which consists of the capability to maintain, modify and create knowledge assets. Each of the perspectives significantly contributes to the understanding of organizationalrenewal capability, and the integrative approach presented in this dissertationcontributes to the individual perspectives as well as to the understanding of organizational renewal capability as a whole.

Experimental insights into deformation dynamics and intermittency in rapid granular shear flows

This work concerns the experimental study of rapid granular shear flows in annular Couette geometry. The flow is induced by continuous driving of the horizontal plate at the top of the granular bed in an annulus. The compressive pressure, driving torque, instantaneous bed height and rotational speed of the shearing plate are measured. Moreover, local stress fluctuations are measured in a medium made of steel spheres 2 and 3 mm in diameter. Both monodisperse packing and bidisperse packing are investigated to reveal the influence of size diversity in intermittent features of granular materials. Experiments are conducted in an annulus that can contain up to 15 kg of spherical steel balls. The shearing granular medium takes place via the rotation of the upper plate which compresses the material loaded inside the annulus. Fluctuations of compressive force are locally measured at the bottom of the annulus using a piezoelectric sensor. Rapid shear flow experiments are pursued at different compressive forces and shear rates and the sensitivity of fluctuations are then investigated by different means through monodisperse and bidisperse packings. Another important feature of rapid granular shear flows is the formation of ordered structures upon shearing. It requires a certain range for the amount of granular material (uniform size distribution) loaded in the system in order to obtain stable flows. This is studied more deeply in this thesis. The results of the current work bring some new insights into deformation dynamics and intermittency in rapid granular shear flows. The experimental apparatus is modified in comparison to earlier investigations. The measurements produce data for various quantities continuously sampled from the start of shearing to the end. Static failure and dynamic shearing ofa granular medium is investigated. The results of this work revealed some important features of failure dynamics and structure formation in the system. Furthermore, some computer simulations are performed in a 2D annulus to examine the nature of kinetic energy dissipation. It is found that turbulent flow models can statistically represent rapid granular flows with high accuracy. In addition to academic outcomes and scientific publications our results have a number of technological applications associated with grinding, mining and massive grain storages.

Extending the canopy flow model for natural, highly flexible macrophyte canopies

Flow structures above vegetation canopies have received much attention within terrestrial and aquatic literature. This research has led to a good process understanding of mean and turbulent canopy flow structure. However, much of this research has focused on rigid or semi-rigid vegetation with relatively simple morphology. Aquatic macrophytes differ from this form, exhibiting more complex morphologies, predominantly horizontal posture in the flow and a different force balance. While some recent studies have investigated such canopies, there is still the need to examine the relevance and applicability of general canopy layer theory to these types of vegetation. Here, we report on a range of numerical experiments, using both semi-rigid and highly flexible canopies. The results for the semi-rigid canopies support existing canopy layer theory. However, for the highly flexible vegetation, the flow pattern is much more complex and suggests that a new canopy model may be required.

Quadrant/octant sequencing and the role of coherent structures in bed load sediment entrainment

To permit the tracking of turbulent flow structures in an Eulerian frame from single-point measurements, we make use of a generalization of conventional two-dimensional quadrant analysis to three-dimensional octants. We characterize flow structures using the sequences of these octants and show how significance may be attached to particular sequences using statistical mull models. We analyze an example experiment and show how a particular dominant flow structure can be identified from the conditional probability of octant sequences. The frequency of this structure corresponds to the dominant peak in the velocity spectra and exerts a high proportion of the total shear stress. We link this structure explicitly to the propensity for sediment entrainment and show that greater insight into sediment entrainment can be obtained by disaggregating those octants that occur within the identified macroturbulence structure from those that do not. Hence, this work goes beyond critiques of Reynolds stress approaches to bed load entrainment that highlight the importance of outward interactions, to identifying and prioritizing the quadrants/octants that define particular flow structures. Key Points <list list-type=''bulleted'' id=''jgrf20196-list-0001''> <list-item id=''jgrf20196-li-0001''>A new method for analysing single point velocity data is presented <list-item id=''jgrf20196-li-0002''>Flow structures are identified by a sequence of flow states (termed octants) <list-item id=''jgrf20196-li-0003''>The identified structure exerts high stresses and causes bed-load entrainment

Expresiones para la determinación del factor de fricción en ríos de fuerte pendiente

Con base en una selección de 145 datos pertenecientes a ríos de montaña de fuerte pendiente (³ 1%) se han desarrollado cinco expresiones para determinar el factor de fricción de Darcy-Weisbach. La primera expresión se fundamenta en la aplicación para flujo turbulento rugoso en lámina libre de la ley semilogarítmica de Prandtl-Kárman, que es función de la sumersión relativa (relación entre el calado medio y la rugosidad equivalente). La segunda y tercera corresponden a correciones de la primera para flujo macrorrugoso, propuestas por Thompson y Campbell (1979) y Aguirre-Pe y Fuentes (1990) respectivamente. La cuarta ecuación consiste una en potencia de la sumersión relativa, mientras que la quinta corrige la fórmula anterior incorporando una potencia de la pendiente, tal y como propugnan Meunier (1989) y Rickenmann (1990). Las expresiones derivadas presentan un ajuste significativo, si se tienen en cuenta las limitaciones hidrométricas existentes en ríos de material grueso y fuerte pendiente. Destaca el mayor ajuste conseguido con las ecuaciones con las ecuaciones del tipo potencial frente a las del tipo semilogarítmico. Se ha encontrado, asimismo, una capacidad de predicción ligeramente superior en aquellas expresiones que incluyen modificaciones respecto a la ecuación original, ecuaciones del tipo segundo, tercero y quinto anteriormente indicado.

Yritysten välisen testaus- ja laboratoriotoiminnan kehittäminen Päijät-Hämeessä

Yritykset tekevät nykyään yhä enemmän yhteistyötä keskenään eli verkostoituvat. Verkostoitumisella haetaan kykyä vastata nopeasti muuttuvan toimintaympäristön haasteisiin. Tässä diplomityössä tutkitaan testaus- ja laboratoriopalveluiden saatavuuden kehittämistä verkostoitumisen keinoin.Alueellisia testaus- ja laboratoriopalveluiden saatavuutta parannetaan valjastamalla käyttöön yritysten yksityisessä käytössä olevat tuotekehityslaboratoriot ja niiden vapaa kapasiteetti. Verkoston ytimen muodostaa teknologiapalvelu, joka hallitsee tietoa yritysten resursseista ja jakaa tätä tietoa. Työssä kartoitettiin alueella olevista yrityksistä heidän tarpeitaan tuotekehityksen aikaiselle testaukselle, tähän sopivia olemassa olevia laitteita ja tiloja ja yritysten mielipiteitä toiminnan organisoimisesta. Lisäksi tutkittiin tuotekehityksen aikana tarvittavaa direktiivitietouden tarvetta yrityksissä. Yritykset suhtautuivat erittäin myönteisesti yhteistyön tekemiseen testaus- ja laboratoriotoiminnassa. Yrityksistä löytyi erilaisia testauslaitteita ja –tiloja, ja näitä on muidenkin yritysten mahdollista käyttää tietyin ehdoin, kunhan se ei häiritse yrityksen omaa tuotekehitystyötä ja vapaata kapasiteettia löytyy.

Kuumalanka-anemometri virtausmittauksissa

Tässä työssä selostetaan kuumalanka-anemometrin käyttö virtausmittauksissa. Kuumalanka-anemometrilla saadaan mitattua virtausnopeuden ja -suunnan lisäksi nopeusheilahteluja. Mittaustaajuus on tyypillisesti useita kymmeniä tuhansia mittauksia sekunnissa ja signaali on jatkuva. Nykytekniikalla pystytään helposti tallentamaan mittauslaitteistolta saatu viesti tietokoneelle ja muuntamaan se nopeudeksi. Hetkellisten nopeuksien avulla voidaan laskea turbulenttisen virtauksen ominaisuuksia, kuten turbulenssin intensiteetti ja spektri. Kuumalanka-anemometrissa lämmitetään sähköisesti ohutta lankaa, joka on mitattavassa virtauksessa. Langan sähköteho on suunnilleen yhtäsuuri kuin langasta konvektiolla siirtyvä lämpöteho. Tällöin on teoreettisesti mahdollista laskea virtausnopeus lämpötehosta lämmönsiirtokorrelaatioilla. Käytännössä laitteisto joudutaan kuitenkin erikseen kalibroimaan, mutta sähkötehon teoreettista riippuvuutta konvektiosta käytetään hyväksi. Kuumalangan lämmitettävä osuus on tyypillisesti halkaisijaltaan 5 µm ja pituudeltaan noin 1 mm. Sitä käytetään pääasiassa kaasuvirtausten mittaamiseen ja valtaosassa mittauksissa virtausaineena on ilma. Kuumalanka voi olla toteutettu kuumakalvotekniikalla, jossa halkaisijaltaan noin 50 - 70 µm paksuinen kuitu on päällystetty ohuella sähköä johtavalla kalvolla. Kuumakalvoanturin ei tarvitse olla muodoltaan sylinterimäinen, se voi olla mm. kartiomainen tai kiilamainen. Erikoispäällystetyllä kuumakalvoanturilla on mahdollista mitata myös nestevirtauksia. Mitattaessa kaasuvirtauksia kuumakalvon etuna on selvästi parempi kestävyys verrattuna kuumalankaan. Nimitystä kuumalanka-anemometri käytetään yleisesti molemmista anturityypeistä Tämän työn alussa käsitellään sylinterin yli tapahtuvaan virtaukseen liittyvää virtausmekaniikkaa ja lämmönsiirtoa. Anemometrin sähköinen osa, laitteisto ja sen kalibrointi käydään läpi. Langan suuntariippuvuuden laskentaan esitetään tarvittavat yhtälöt. Työssä esitellään kolme laitteistolla tehtyä perusmittausta: anturin kohtauskulman muuttaminen, pyörähdyssymmerisen suihkun nopeuskenttä ja tuulitunnelin rajakerros. Lisäksi esitellään yksi käytännöllinen ja vaativampi mittaus, jossa on mitattu nopeusprofiili radiaalikompressorin diffuusorin loppuosassa.