32 resultados para All plastic clean surface pumped supply
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
Kuparipinnan hapettumisen alkuvaiheet ovat vielä nykyisin tutkijoille epäselviä. Kuitenkin, jotta hapettumisprosessia voitaisiin säädellä, on sangen tärkeää ymmärtää mistä varsinainen hapettuminen lähtee liikkeelle ja mitkä ovat hapettumisen seuraavat vaiheet. Tähän kysymykseen haetaan vastauksia tässä työssä käyttäen puhtaasti teoreettisia menetelmiä pinnan käsittelyssä. Aikaisempien teoreettisten ja kokeellisten tutkimusten välillä on pieni ristiriita liittyen hapen tarttumistodennäköisyyteen. Teoreettisten tutkimusten mukaan happi ei puhtaalle pinnalle tullessaan näe potentiaalivallia, mutta kokeelliset tutkimukset osoittavat sellaisen kuitenkin olevan. Tuohon ristiriitaan pureudutaan käyttäen aikaisemmista laskuista poikkeavaa kvanttimekaaniseen molekyylidynamiikkaan perustuvaa lähestymistapaa. Työssä havaitaan, että aikaisemmin yleisesti käytetty menetelmä hukkaa huomattavan määrän tietoa ja siten tutkijat eivät voi ainoastaan tyytyä tarkastelemaan kyseisellä menetelmällä saatuja tuloksia. Kuparipinnalle havaittiin, että korkeilla molekyylin kineettisen energian arvolla aikaisemmin suoritetut laskut hajottavista trajektoreista pitävät paikkansa, mutta matalilla kineettisen energian arvoilla molekyyli kohtaa erittäin voimakkaan ``steering'' vaikutuksen ja trajektorit joiden piti olla hajottavia johtavatkin molekulaariseen adsorptioon. Kun hapen konsentraatio pinnalla on suurempi kuin 0.5 ML, pinta rekonstruoituu. Myös rekonstruktion jälkeistä pintaa on tutkittu samanlaisilla menetelmillä kuin puhdasta pintaa. Rekonstruoituneelle pinnalle ei löydetty hajottavia trajektoreita ja havaittiin, että hapelle annetun kineettisen energian matalilla arvoilla myös tässä tapauksessa on erittäin voimakas ``steering'' vaikutus.
Resumo:
Paperin pinnan karheus on yksi paperin laatukriteereistä. Sitä mitataan fyysisestipaperin pintaa mittaavien laitteiden ja optisten laitteiden avulla. Mittaukset vaativat laboratorioolosuhteita, mutta nopeammille, suoraan linjalla tapahtuville mittauksilla olisi tarvetta paperiteollisuudessa. Paperin pinnan karheus voidaan ilmaista yhtenä näytteelle kohdistuvana karheusarvona. Tässä työssä näyte on jaettu merkitseviin alueisiin, ja jokaiselle alueelle on laskettu erillinen karheusarvo. Karheuden mittaukseen on käytetty useita menetelmiä. Yleisesti hyväksyttyä tilastollista menetelmää on käytetty tässä työssä etäisyysmuunnoksen lisäksi. Paperin pinnan karheudenmittauksessa on ollut tarvetta jakaa analysoitava näyte karheuden perusteella alueisiin. Aluejaon avulla voidaan rajata näytteestä selvästi karheampana esiintyvät alueet. Etäisyysmuunnos tuottaa alueita, joita on analysoitu. Näistä alueista on muodostettu yhtenäisiä alueita erilaisilla segmentointimenetelmillä. PNN -menetelmään (Pairwise Nearest Neighbor) ja naapurialueiden yhdistämiseen perustuvia algoritmeja on käytetty.Alueiden jakamiseen ja yhdistämiseen perustuvaa lähestymistapaa on myös tarkasteltu. Segmentoitujen kuvien validointi on yleensä tapahtunut ihmisen tarkastelemana. Tämän työn lähestymistapa on verrata yleisesti hyväksyttyä tilastollista menetelmää segmentoinnin tuloksiin. Korkea korrelaatio näiden tulosten välillä osoittaa onnistunutta segmentointia. Eri kokeiden tuloksia on verrattu keskenään hypoteesin testauksella. Työssä on analysoitu kahta näytesarjaa, joidenmittaukset on suoritettu OptiTopolla ja profilometrillä. Etäisyysmuunnoksen aloitusparametrit, joita muutettiin kokeiden aikana, olivat aloituspisteiden määrä ja sijainti. Samat parametrimuutokset tehtiin kaikille algoritmeille, joita käytettiin alueiden yhdistämiseen. Etäisyysmuunnoksen jälkeen korrelaatio oli voimakkaampaa profilometrillä mitatuille näytteille kuin OptiTopolla mitatuille näytteille. Segmentoiduilla OptiTopo -näytteillä korrelaatio parantui voimakkaammin kuin profilometrinäytteillä. PNN -menetelmän tuottamilla tuloksilla korrelaatio oli paras.
Resumo:
In order that the radius and thus ununiform structure of the teeth and otherelectrical and magnetic parts of the machine may be taken into consideration the calculation of an axial flux permanent magnet machine is, conventionally, doneby means of 3D FEM-methods. This calculation procedure, however, requires a lotof time and computer recourses. This study proves that also analytical methods can be applied to perform the calculation successfully. The procedure of the analytical calculation can be summarized into following steps: first the magnet is divided into slices, which makes the calculation for each section individually, and then the parts are submitted to calculation of the final results. It is obvious that using this method can save a lot of designing and calculating time. Thecalculation program is designed to model the magnetic and electrical circuits of surface mounted axial flux permanent magnet synchronous machines in such a way, that it takes into account possible magnetic saturation of the iron parts. Theresult of the calculation is the torque of the motor including the vibrations. The motor geometry and the materials and either the torque or pole angle are defined and the motor can be fed with an arbitrary shape and amplitude of three-phase currents. There are no limits for the size and number of the pole pairs nor for many other factors. The calculation steps and the number of different sections of the magnet are selectable, but the calculation time is strongly depending on this. The results are compared to the measurements of real prototypes. The permanent magnet creates part of the flux in the magnetic circuit. The form and amplitude of the flux density in the air-gap depends on the geometry and material of the magnetic circuit, on the length of the air-gap and remanence flux density of the magnet. Slotting is taken into account by using the Carter factor in the slot opening area. The calculation is simple and fast if the shape of the magnetis a square and has no skew in relation to the stator slots. With a more complicated magnet shape the calculation has to be done in several sections. It is clear that according to the increasing number of sections also the result will become more accurate. In a radial flux motor all sections of the magnets create force with a same radius. In the case of an axial flux motor, each radial section creates force with a different radius and the torque is the sum of these. The magnetic circuit of the motor, consisting of the stator iron, rotor iron, air-gap, magnet and the slot, is modelled with a reluctance net, which considers the saturation of the iron. This means, that several iterations, in which the permeability is updated, has to be done in order to get final results. The motor torque is calculated using the instantaneous linkage flux and stator currents. Flux linkage is called the part of the flux that is created by the permanent magnets and the stator currents passing through the coils in stator teeth. The angle between this flux and the phase currents define the torque created by the magnetic circuit. Due to the winding structure of the stator and in order to limit the leakage flux the slot openings of the stator are normally not made of ferromagnetic material even though, in some cases, semimagnetic slot wedges are used. In the slot opening faces the flux enters the iron almost normally (tangentially with respect to the rotor flux) creating tangential forces in the rotor. This phenomenon iscalled cogging. The flux in the slot opening area on the different sides of theopening and in the different slot openings is not equal and so these forces do not compensate each other. In the calculation it is assumed that the flux entering the left side of the opening is the component left from the geometrical centre of the slot. This torque component together with the torque component calculated using the Lorenz force make the total torque of the motor. It is easy to assume that when all the magnet edges, where the derivative component of the magnet flux density is at its highest, enter the slot openings at the same time, this will have as a result a considerable cogging torque. To reduce the cogging torquethe magnet edges can be shaped so that they are not parallel to the stator slots, which is the common way to solve the problem. In doing so, the edge may be spread along the whole slot pitch and thus also the high derivative component willbe spread to occur equally along the rotation. Besides forming the magnets theymay also be placed somewhat asymmetric on the rotor surface. The asymmetric distribution can be made in many different ways. All the magnets may have a different deflection of the symmetrical centre point or they can be for example shiftedin pairs. There are some factors that limit the deflection. The first is that the magnets cannot overlap. The magnet shape and the relative width compared to the pole define the deflection in this case. The other factor is that a shifting of the poles limits the maximum torque of the motor. If the edges of adjacent magnets are very close to each other the leakage flux from one pole to the other increases reducing thus the air-gap magnetization. The asymmetric model needs some assumptions and simplifications in order to limit the size of the model and calculation time. The reluctance net is made for symmetric distribution. If the magnets are distributed asymmetrically the flux in the different pole pairs will not be exactly the same. Therefore, the assumption that the flux flows from the edges of the model to the next pole pairs, in the calculation model from one edgeto the other, is not correct. If it were wished for that this fact should be considered in multi-pole pair machines, this would mean that all the poles, in other words the whole machine, should be modelled in reluctance net. The error resulting from this wrong assumption is, nevertheless, irrelevant.
Resumo:
Quality inspection and assurance is a veryimportant step when today's products are sold to markets. As products are produced in vast quantities, the interest to automate quality inspection tasks has increased correspondingly. Quality inspection tasks usuallyrequire the detection of deficiencies, defined as irregularities in this thesis. Objects containing regular patterns appear quite frequently on certain industries and science, e.g. half-tone raster patterns in the printing industry, crystal lattice structures in solid state physics and solder joints and components in the electronics industry. In this thesis, the problem of regular patterns and irregularities is described in analytical form and three different detection methods are proposed. All the methods are based on characteristics of Fourier transform to represent regular information compactly. Fourier transform enables the separation of regular and irregular parts of an image but the three methods presented are shown to differ in generality and computational complexity. Need to detect fine and sparse details is common in quality inspection tasks, e.g., locating smallfractures in components in the electronics industry or detecting tearing from paper samples in the printing industry. In this thesis, a general definition of such details is given by defining sufficient statistical properties in the histogram domain. The analytical definition allowsa quantitative comparison of methods designed for detail detection. Based on the definition, the utilisation of existing thresholding methodsis shown to be well motivated. Comparison of thresholding methods shows that minimum error thresholding outperforms other standard methods. The results are successfully applied to a paper printability and runnability inspection setup. Missing dots from a repeating raster pattern are detected from Heliotest strips and small surface defects from IGT picking papers.
Resumo:
Tämän diplomityön tarkoituksena oli tutkia pintaliimatärkkelysten reologista käyttäytymistä korkeissa kuiva-ainepitoisuuksissa. Tarve työn suorittamiselle syntyi kun tutkittiin pintaliimausta filminsiirtopuristimella tavallista korkeammissa kuiva-ainepitoisuuksissa, sileän sauvan ollessa applikointilaitteena. Koska applikointi sileällä sauvalla tapahtuu hydrodynaamisten periaatteiden mukaisesti, sen käyttö edellyttää pintaliimojen reologisten ominaisuuksien tarkkaa tuntemusta ja hallintaa.Kiinnostuksen kohteena olevat ominaisuudet olivat tärkkelysten kuiva-ainepitoisuuden (8 – 30 %) vaikutus viskositeettiin eri lämpötiloissa (20, 30, 40 ja 50 ºC), leikkausnopeus alueella 1 s-1 - 700 000 s-1. Myös tärkkelysten myötörajat määritettiin tutkimuksessa. Viskositeetti eri leikkausnopeusalueilla mitattiin seuraavilla laitteilla: Bohlin VOR (matalat leikkausnopeudet ja myötöraja) ja Hercules HiShear (keskitason leikkausnopeudet) reometrit sekä Eklund kapillaariviskometri (korkeat leikkausno-peudet). Analysoidut tärkkelykset olivat kaksi anionista matalaviskoottista peruna (tärkkelys A) ja ohra (tärkkelys C) tärkkelystä, sekä yksi kationinen korkeaviskoottinen peruna tärkkelys (tärkkelys B). Tutkittujen tärkkelysten Brookfield viskositeetit (100 rpm) olivat (10 % liuos, 60 °C:ssa) tärkkelys A ja C: 25 ± 5 mPas ja tärkkelys B: 100 ± 20 mPas.Tärkkelysliuosten kuiva-ainepitoisuuden noustessa muuttui virtauskäyttäytyminen Newtoniaalisesta leikkausohenevaksi. Leikkausoheneva käyttäytyminen oli voimakkainta tärkkelys B:n kohdalla. Viskositeetti – lämpötila riippuvuus korkeissa leikkausnopeuksissa (esim. 500 000 s-1) oli vähäisempää, mitä oli oletettavissa Brookfield viskositeettiarvojen perusteella. Kaikki tarkkelykset osoittautuivat tiksotrooppisiksi, myös tiksotrooppisuus lisääntyi kuiva-ainepitoisuuden kasvaessa. Tärkkelysten myötörajat osoittautuivat odottamattoman alhaisiksi, kuitenkin varsinkin tärkkelys B:n myötörajat olivat selvästi riippuvaisia lämpötilasta ja kuiva-ainepitoisuudesta. Tutkittujen tärkkelysten virtauskäyttäytyminen oli kirjallisuudessa esitetyn kaltaista. Tärkkelysmolekyylien ketjun pituus oli tärkein tärkkelyksen reologisia ominaisuuksia määrittävä tekijä; mitä matalampi on tärkkelyksen molekyylimassa, sitä matalammat ovat viskositeetti ja myötöraja. Pintaliimauksessa tärkkelysmolekyylien ketjunpituudella on suuri vaikutus ajettavuuteen ja lopputuotteen ominaisuuksiin. Haasteellista pintaliimatärkkelyksen valinnassa on sellaisen yhdistelmän löytäminen, jossa sopivan reologisen käyttäytymisen omaava tärkkelys ja pintaliimatulle paperille tai kartongille asetetut vaatimukset kohtaavat.
Resumo:
Organizations gain resources, skills and technologies to find out the ultimate mix of capabilities to be a winner in the competitive market. These are all important factors that need to be taken into account in organizations operating in today's business environment. So far, there are no significant studies on the organizational capabilities in the field of PSM. The literature review shows that the PSM capabilities need to be studied more comprehensively. This study attempts to reveal and fill this gap by providing the PSM capability matrix that identifies the key PSM capabilities approached from two angles: there are three primary PSM capabilities and nine subcapabilities and, moreover, the individual and organizational PSM capabilities are identified and evaluated. The former refers to the PSM capability matrix of this study which is based on the strategic and operative PSM capabilities that complement the economic ones, while the latter relates to the evaluation of the PSM capabilities, such as the buyer profiles of individual PSM capabilities and the PSMcapability map of the organizational ones. This is a constructive case study. The aim is to define what the purchasing and supply management capabilities are and how they can be evaluated. This study presents a PSM capability matrix to identify and evaluate the capabilities to define capability gaps by comparing the ideal level of PSM capabilities to the realized ones. The research questions are investigated with two case organizations. This study argues that PSM capabilities can be classified into three primary categories with nine sub-categories and, thus, a PSM capability matrix with four evaluation categories can be formed. The buyer profiles are moreover identified to reveal the PSM capability gap. The resource-based view (RBV) and dynamic capabilities view (DCV) are used to define the individual and organizational capabilities. The PSM literature is also used to define the capabilities. The key findings of this study are i) the PSM capability matrix to identify the PSM capabilities, ii) the evaluation of the capabilities to define PSM capability gaps and iii) the presentation of the buyer profiles to identify the individual PSM capabilities and to define the organizational PSM capabilities. Dynamic capabilities are also related to the PSM capability gap. If a gap is identified, the organization can renew their PSM capabilities and, thus, create mutual learning and increase their organizational capabilities. And only then, there is potential for dynamic capabilities. Based on this, the purchasing strategy, purchasing policy and procedures should be identified and implemented dynamically.
Resumo:
Purchasing and supply management (PSM) has become increasingly important for companies to survive in current highly competitive market. Increased outsourcing has extended the role of PSM, making external resource management and supplier relationships critical success factors in business. However, the recent research has mainly concentrated on large enterprises. Therefore the PSM issues related to medium-sized enterprises represent a significant research area. The thesis aims to explore the status and role of PSM in Finnish medium-sized firms, understand how strategic companies consider PSM to be, clarify what are the competence requirements for PSM professionals, and increase the understanding of PSM capabilities needed from the points view of individual competence and organisational capabilities. The study uses data that was collected in 2007 from purchasing executives at the director/CEO level representing a sample of 94 Finnish firms. 54 % of the respondent enterprises had a supply strategy. The total supply cost was on average 60 % of firms' turnover. Centralisation of PSM and outsourcing of logistics will increase in Finnish medium-sized enterprises. The findings point out that Finnish medium-sized enterprises had strategical features of PSM. However, Finnish firms have not concentrated on making strategies that relate to PSM. The elements that explain the existence of a supply strategy could be found in this study. It can be concluded from this study that there is an advantageous base for the development of strategic PSM, because nearly all the enterprises were of the opinion that PSM capabilities have an effect on business success. When reviewing the organisational capabilities, the five most important development elements were supplier relationships, both operational and strategic processes, time management, and personnel's competence. Training in internationalisation, strategic management, and communication could help to improve competences of PSM personnel.
Resumo:
Building industry is a high volume branch which could provide prominent markets for wood based interior decoration solutions. Competition in interior decoration markets requires versatility in appearance. Versatility in wood appearance and added value could be achieved by printing grain patterns of different species or images directly onto wood. The problem when planning wood printing’s implementing into durable applications is basically how to transfer a high quality image or print sustainably onto wood, which is porous, heterogeneous, dimensionally unstable, non-white and rough. Wood preservation or treating, and modification can provide durability against degradation but also effect to the surface properties of wood which will effect on printability. Optimal adhesion is essential into print quality, as too high ink absorbance can cause spreading and too low ink absorbance cause pale prints. Different printing techniques have different requirements on materials and production. The direct printing on wood means, that intermedias are not used. Printing techniques with flexible printing plates or in fact non-impact techniques provide the best basis for wood printing. Inkjet printing of wood with different mechanical or chemical surface treatments, and wood plastic composite material gave good results that encourage further studies of the subject. Sanding the wood surface anti-parallel to the grain gave the best overall printing quality. Spreading parallel to the grain could not be avoided totally, except in cases where wood was treated hydrophobic so adhesion of the ink was not sufficient. Grain pattern of the underlying wood stays clearly visible in the printed images. Further studies should be made to fine tune the methods that already gave good results. Also effects of moisture content of wood, different inks, and long-term exposure to UV-radiation should be tested.
Resumo:
Succeeding in small board lot (0-20 tons) deliveries, is not always prosperous and failures as well as extra costs compared to standard costs arise. Failure deliveries from converting plants to customer locations tie a lot of unwanted and unexpected costs. Extra costs are handled as quality costs and more precise, internal failure costs. These costs revolve from unsuccessful truck payloads, redundant warehousing or unfavorable routing as examples. Quality costs are becoming more and more important factor in company’s financial decision making. Actual, realized truck payload correlates with the extra costs occurring, so filling the truck payload all get-out well is a key to lower the extra costs. Case company in this study is Corporation A, business segment Boards. Boards have outsourced half of their converting in order to gain better customer service via flexibility, lead time reductions and logistics efficiency improvements. Examination period of the study is first two quarters of year 2008 and deliveries examined are from converters to the customer locations. In Corporation A’s case, the total loss in failure deliveries is hundreds of thousands of Euros during the examination period. So, the logistics goal of getting the right product to the right place and right time for the least cost, does not completely realize.
Resumo:
The environmental challenges of plastic packaging industry have increased remarkably along with climate change debate. The interest to study carbon footprints of packaging has increased in packaging industry to find out the real climate change impacts of packaging. In this thesis the greenhouse gas discharges of plastic packaging during their life cycle is examined. The carbon footprint is calculated for food packaging manufactured from plastic laminate. The structure of the laminate is low density polyethylene (PE-LD) and oriented polypropylene (OPP), which have been joined together with laminating adhesive. The purpose is to find out the possibilities to create a carbon footprint calculating tool for plastic packaging and its usability in a plastic packaging manufacturing company. As a carbon footprint calculating method PAS 2050 standard has been used. In the calculations direct and indirect greenhouse gas discharges as well as avoided discharges are considered. Avoided discharges are born for example in packaging waste utilization as energy. The results of the calculations have been used to create a simple calculating tool to be used for similar laminate structures. Although the utilization of the calculating tool is limited to one manufacturing plant because the primary activity data is dependent of geographical location and for example the discharges of used energy in the plant. The results give an approximation of the climate change potential caused by the laminate. It is although noticed that calculations do not include all environmental impacts of plastic packaging´s life cycle.
Resumo:
Dental oxide ceramics have been inspired by their biocompability and mechanical properties which have made durable all-ceramic structures possible. Clinical longevity of the prosthetic structures is dependent on effective bonding with luting cements. As the initial shear bond strength values can be comparable with several materials and procedures, long-term durability is affected by ageing. Aims of the current study were: to measure the shear bond strength of resin composite-to-ceramics and to evaluate the longevity of the bond; to analyze factors affecting the bond, with special emphasis on: the form of silicatization of the ceramic surface; form of silanization; type of resin primer and the effect of the type of the resin composite luting cement; the effect of ageing in water was studied regarding its effect to the endurance of the bond. Ceramic substrates were alumina and yttrium stabilized zirconia. Ceramic conditioning methods included tribochemical silicatization and use of two silane couplings agents. A commercial silane primer was used as a control silane. Various combinations of conditioning methods, primers and resin cements were tested. Bond strengths were measured by shear bond strength method. The longevity of the bond was generally studied by thermocycling the materials in water. Additionally, in one of the studies thermal cycling was compared with long-term water storaging. Results were analysed statistically with ANOVA and Weibull analysis. Tribochemical treatment utilizing air pressure of 150 kPa resulted shear bond strengths of 11.2 MPa to 18.4 MPa and air pressure of 450 kPa 18.2 MPa to 30.5 MPa, respectively. Thermocycling of 8000 cycles or four years water storaging both decreased shear bond strength values to a range of 3.8 MPa to 7.2 MPa whereas initial situation varied from 16.8. Mpa to 23.0 MPa. The silane used in studies had no statistical significance. The use of primers without 10-MDP resulted spontaneous debonding during thermocycling or shear bond strengths below 5 MPa. As conclusion, the results showed superior long-term bonding with primers containing 10-MDP. Silicatization with silanizing showed improved initial shear bond strength values which considerably decreased with ageing in water. Thermal cycling and water storing for up to four years played the major role in reduction of bond strength, which could be due to thermal fatigue of the bonding interface and hydrolytic degradation of the silane coupled interface.
Resumo:
The paper industry is constantly looking for new ideas for improving paper products while competition and raw material prices are increasing. Many paper products are pigment coated. Coating layer is the top layer of paper, thus by modifying coating pigment also the paper itself can be altered and value added to the final product. In this thesis, synthesis of new plastic and hybrid pigments and their performance in paper and paperboard coating is reported. Two types of plastic pigments were studied: core-shell latexes and solid beads of maleimide copolymers. Core-shell latexes with partially crosslinked hydrophilic polymer core of poly(n-butyl acrylate-co-methacrylic acid) and a hard hydrophobic polystyrene shell were prepared to improve the optical properties of coated paper. In addition, the effect of different crosslinkers was analyzed and the best overall performance was achieved by the use of ethylene glycol dimethacrylate (EGDMA). Furthermore, the possibility to modify core-shell latex was investigated by introducing a new polymerizable optical brightening agent, 1-[(4-vinylphenoxy)methyl]-4-(2-henylethylenyl)benzene which gave promising results. The prepared core-shell latex pigments performed smoothly also in pilot coating and printing trials. The results demonstrated that by optimizing polymer composition, the optical and surface properties of coated paper can be significantly enhanced. The optimal reaction conditions were established for thermal imidization of poly(styrene-co-maleimide) (SMI) and poly(octadecene-co-maleimide) (OMI) from respective maleic anhydride copolymer precursors and ammonia in a solvent free process. The obtained aqueous dispersions of nanoparticle copolymers exhibited glass transition temperatures (Tg) between 140-170ºC and particle sizes from 50-230 nm. Furthermore, the maleimide copolymers were evaluated in paperboard coating as additional pigments. The maleimide copolymer nanoparticles were partly imbedded into the porous coating structure and therefore the full potential of optical property enhancement for paperboard was not achieved by this method. The possibility to modify maleimide copolymers was also studied. Modifications were carried out via N-substitution by replacing part of the ammonia in the imidization reaction with amines, such as triacetonediamine (TAD), aspartic acid (ASP) and fluorinated amines (2,2,2- trifluoroethylamine, TFEA and 2,2,3,3,4,4,4-heptafluorobuthylamine, HFBA). The obtained functional nanoparticles varied in size between 50-217 nm and their Tg from 150-180ºC. During the coating process the produced plastic pigments exhibited good runnability. No significant improvements were achieved in light stability with TAD modified copolymers whereas nanoparticles modified with aspartic acid and those containing fluorinated groups showed the desired changes in surface properties of the coated paperboard. Finally, reports on preliminary studies with organic-inorganic hybrids are presented. The hybrids prepared by an in situ polymerization reaction consisted of 30 wt% poly(styrene- co-maleimide) (SMI) and high levels of 70 wt% inorganic components of kaolin and/or alumina trihydrate. Scanning Electron Microscopy (SEM) images and characterization by Fourier Transform Infrared Spcetroscopy (FTIR) and X-Ray Diffraction (XRD) revealed that the hybrids had conventional composite structure and inorganic components were covered with precipitated SMI nanoparticles attached to the surface via hydrogen bonding. In paper coating, the hybrids had a beneficial effect on increasing gloss levels.
Resumo:
The objective of this thesis is to define supply management capability. The thesis study what factors consist of supply management capability, and which of those factors are critical to achieving competitive advantage. One objective is also to study how firms can measure their supply management capability. This study is a qualitative research. The thesis examines the literature regarding to supply management and the context of capability and there are used Delphi panel to examine the current and future insights of supply management professionals concerning of supply management skills and capability. The empirical data of the thesis was collected by interviews. The Delphi panel was used in data collection and analysis and for prioritization of the factors of supply management capability. The thesis includes lists of factors of supply management capability. Main findings of the study were that there is no one clear, generally suitable set of supply management skills which bring competitive advantage for all firms and the most important factors of supply management capability, according to the experts, are total cost analysis, customer focus, general business view, market knowledge and supplier relationships. In this study the supply management capability is defined as organization’s overall capacity and ability to achieve a holistic understanding of purchasing needs, manage its suppliers and collaborative partners, and conduct its internal tasks, routines and responsibilities in a way that achieves desired results. The results of this thesis show also that Finnish firms need more right kind of supply management knowledge.
Resumo:
In this study we discuss the atomic level phenomena on transition metal surfaces. Transition metals are widely used as catalysts in industry. Therefore, reactions occuring on transition metal surfaces have large industrial intrest. This study addresses problems in very small size and time scales, which is an important part in the overall understanding of these phenomena. The publications of this study can be roughly divided into two categories: The adsorption of an O2 molecule to a surface, and surface structures of preadsorbed atoms. These two categories complement each other, because in the realistic case there are always some preadsorbed atoms at the catalytically active surfaces. However, all transition metals have an active d-band, and this study is also a study of the in uence of the active d-band on other atoms. At the rst part of this study we discuss the adsorption and dissociation of an O2 molecule on a clean stepped palladium surface and a smooth palladium surface precovered with sulphur and oxygen atoms. We show how the reactivity of the surface against the oxygen molecule varies due to the geometry of the surface and preadsorbed atoms. We also show how the molecular orbitals of the oxygen molecule evolve when it approaches the di erent sites on the surface. In the second part we discuss the surface structures of transition metal surfaces. We study the structures that are intresting on account of the Rashba e ect and charge density waves. We also study the adsorption of suphur on a gold surface, and surface structures of it. In this study we use ab-initio based density functional theory methods to simulate the results. We also compare the results of our methods to the results obtained with the Low-Energy-Electron-Difraction method.
Resumo:
Mikkelin talousvedestä kahden kolmasosan tullessa Pursialan pohjavesialueelta on alueen suojeleminen tärkeää. Pohjaveden laatua uhkaavat etenkin alueella sattuneet pohjavedenpilaantumistapaukset. Merkittävimmät pohjaveden pilaantumistapaukset ovat VAPO Oy:n sahan aiheuttama pohjaveden pilaantuminen kloorifenoleilla (CP) ja VR:n ratapölkkykyllästämön aiheuttama pohjaveden pilaantuminen kreosoottiöljyllä sekä Rinnekadun Nesteen aiheuttama pohjaveden pilaantuminen MTBE:llä. Alueella on tehty tutkimuksia ja kunnostuksia pilaantumiin liittyen, mutta näiden tuloksia ei ole aikaisemmin koottu yhteen. Tämän työn tavoitteena oli koota tulokset samaan aineistoon. Työssä keskityttiin kloorifenolien leviämisen tarkasteluun sen Pursialan pohjavedenottamolle muodostaman suurimman uhan vuoksi. Kallioperätietojen, maanpintatietojen ja näytetietojen pohjalta laadittiin myös pienoismalli CP-pilaantuman leviämisen kokonaiskuvan hahmottamiseksi. Työn tavoitteena oli lisäksi tehdä riskitarkastelua CP-pilaantumaan liittyen ja etsiä keinoja hallita havaittuja riskejä. Riskinhallintaan liittyen työssä tutkittiin kloorifenoleilla pilaantuneen alueen maaperä- ja kalliotietoja sekä pohjaveden laatutietoja. Pursialan pohjavedessä on runsaasti rautaa ja mangaania sekä aggressiivista hiilihappoa. Pohjaveden pH on alueella noin 6,5, lämpötila noin 7,5 ºC ja happipitoisuus noin 0,7 mg/l. Pursialan kaupunginalueen kallioperässä on havaittavissa VAPO Oy:n sahalta vedenottamolle etenevä kalliopainanne, jota pitkin CP etenee. Alueen kallioperä on kiillegneissiä, jossa on pohjois–etelä-suuntaista rakoilua. Maaperätuloksien perusteella on havaittavissa vettä hyvin johtavien maakerrosten jatkuminen koko vedenottamon ja sahan välisen matkan, mikä tarkoittaa, että CP-pitoisella pohjavedellä voi olla aiemmin oletettua nopeampikin yhteys sahalta vedenottamolle. Suurin CP-pitoisuus noin 100 000 µg/l on mitattu KY-5-altaan kohdalle asennetun M14-pohjavesiputken pohjasta. Talousvesiasetuksen raja-arvo CP:lle on 10 µg/l. Sahan ja vedenottamon puolivälissä on havaittu yli 10 000 µg/l meneviä CP-pitoisuuksia. Suurin vedenottamon kaivoista (kaivo 10) mitattu pitoisuus on 149 µg/l. Jakotukilta raakavedestä otetuissa näytteissä tai talousvedessä ei ole kuitenkaan havaittu talousvesiasetuksen ylittäviä CP-pitoisuuksia. Pienoismallin perusteella CP sijaitsee sahan alueella lähellä kallionpintaa ja hajaantuu koko pohjavesipatjaan vedenottamolle päin mentäessä. CP-mittaustuloksissa on havaittavissa pulssimaisuutta. Tämä johtuu todennäköisesti Saimaan pinnan vaihtelun seurauksena muuttuvasta rantaimeytyneen pohjaveden määrästä. Saimaan pinnan nousu näyttäisi tuloksien perusteella nostavan CP-pitoisuuksia saha-alueella ja laskevan lähellä vedenottamoa. Pohjaveden pintatietojen perusteella tehdyn tarkastelun mukaan pohjavesi voi kulkeutua sahalta vedenottamolle parhaimmillaan noin vuodessa. Työssä arvioitiin KY-5–liuoksen vuosittaiseksi käyttömääräksi noin 648–970 m3. Allassakkaa arvioitiin syntyneen yhteensä noin 10–31 m3. Pohjaveteen arvioitiin joutuneen toiminnan aikana yhteensä noin 3 000–4 000 kg CP:tä. Kloorifenolit esiintyvät pohjavedessä lähes täysin kloorifenolaatteina. Kloorifenolien hajoaminen ja muuntuminen pohjavedessä on epätodennäköistä. Käsitteellisen mallin mukaan kloorifenolipilaantuman suurimmat riskit aiheutuvat kloorifenolien mahdollisuudesta pilata Pursialan vedenottamon talousvesi. Tällä hetkellä riskejä hallitaan kloorifenolien leviämisen tarkkailulla, sahan ja vedenottamon puolivälissä sijaitsevalla koepumppauksella sekä varautumalla aktiivihiilijauheen syöttöön talousvesiprosessiin. Koepumppauksen avulla on saatu ylös tällä hetkellä noin 69 kg kloorifenoleita. Tutkimuksen perusteella suositeltavimmat riskinhallintatoimet tulevaisuudessa ovat sahalla sijaitseva kunnostuspumppaus, sahan ja vedenottamon väliin sijoittuva suojapumppaus- ja vesiverhoyhdistelmä sekä sahan rannan kautta tapahtuvan rantaimeytymisen estäminen.