Diesel/biodiesel soot oxidation with ceo2 and ceo2-zro2-modified cordierites: a facile way of accounting for their catalytic ability in fuel combustion processes

CeO2 and mixed CeO2-ZrO2 nanopowders were synthesized and efficiently deposited onto cordierite substrates, with the evaluation of their morphologic and structural properties through XRD, SEM, and FTIR. The modified substrates were employed as outer heterogeneous catalysts for reducing the soot originated from the diesel and diesel/biodiesel blends incomplete combustion. Their activity was evaluated in a diesel stationary motor, and a comparative analysis of the soot emission was carried out through diffuse reflectance spectroscopy. The analyses have shown that the catalyst-impregnated cordierite samples are very efficient for soot oxidation, being capable of reducing the soot emission in more than 60%.

Surface Modification of Ceramics

Ceramics are widely used in industrial applications due to their advantageous thermal and mechanical stability. Corrosion of ceramics is a great problem resulting in significant costs. Coating is one method of reducing adversities of corrosion. There are several different thin film deposition processes available such as sol-gel, Physical and Chemical Vapour Deposition (PVD and CVD). One of the CVD processes, called Atomic Layer Deposition (ALD) stands out for its excellent controllability, accuracy and wide process capability. The most commonly mentioned disadvantage of this method is its slowness which is partly compensated by its capability of processing large areas at once. Several factors affect the ALD process. Such factors include temperature, the grade of precursors, pulse-purge times and flux of precursors as well as the substrate used. Wrongly chosen process factors may cause loss of self-limiting growth and thus, non-uniformities in the deposited film. Porous substrates require longer pulse times than flat surfaces. The goal of this thesis was to examine the effects of ALD films on surface properties of a porous ceramic material. The analyses applied were for permeability, bubble point pressure and isoelectric point. In addition, effects of the films on corrosion resistance of the substrate in aqueous environment were investigated. After being exposured to different corrosive media the ceramics and liquid samples collected were analysed both mechanically and chemically. Visual and contentual differences between the exposed and coated ceramics versus the untreated and uncoated ones were analysed by scanning electron microscope. Two ALD film materials, dialuminium trioxide and titanium dioxide were deposited on the ceramic substrate using different pulse times. The results of both film materials indicated that surface properties of the ceramic material can be modified to some extent by the ALD method. The effect of the titanium oxide film on the corrosion resistance of the ceramic samples was observed to be fairly small regardless of the pulse time.

Microwave Processes in Ferrite-ferroelectric Layered Structure

This work is devoted to investigation of wave processes in new hybrid ferrite/ferroelectric structures. Spin wave devices based on ferrite films have disadvanteges. And their applications are limited. Investigated structures allow to overcome disadvantages. This investigation helps to create new class of devices. Electromagnetic analysis of hybrid spin-electromagnetic waves in ferrite/ferroelectric structures were done. As a result dispersion relation was found. Numerical solution of this dispersion relation gave us follow results. These structures can be effectively tuned by external electric and magnetic field. Methods to increase tuning range were suggested. It was found that such structures have one basic disadvantage which is connected with presence of thick ferroelectric layer. To solve this problem is to use thin ferroelectric films. But this decreases tuning range. It was confirmed by experiment that this structures can be effectively tuned by electric and magnetic fields. Resonance characteristics of ferrite/ferroelectric resonator were succesfully tuned by magnetic and electric field.

Quality and analysis of administration processes in server operations

IT outsourcing refers to the way companies focus on their core competencies and buy the supporting functions from other companies specialized in that area. Service is the total outcome of numerous of activities by employees and other resources to provide solutions to customers' problems. Outsourcing and service business have their unique characteristics. Service Level Agreements quantify the minimum acceptable service to the user. The service quality has to be objectively quantified so that its achievement or non-achievement of it can be monitored. Usually offshoring refers to the transferring of tasks to low-cost nations. Offshoring presents a lot of challenges that require special attention and they need to be assessed thoroughly. IT Infrastructure management refers to installation and basic usability assistance of operating systems, network and server tools and utilities. ITIL defines the industry best practices for organizing IT processes. This thesis did an analysis of server operations service and the customers’ perception of the quality of daily operations. The agreed workflows and processes should be followed better. Service providers’ processes are thoroughly defined but both the customer and the service provider might disobey them. Service provider should review the workflows regarding customer functions. Customer facing functions require persistent skill development, as they communicate the quality to the customer. Service provider needs to provide better organized communication and knowledge exchange methods between the specialists in different geographical locations.

Suitability of foam coating on application of thin liquid films

This work aimed to find out the suitability of foam as medium in application of thin liquid films. This consists of research over phenomena related to foam physics and behaviour. Solutions and mixtures to be foamed, foaming agents, foam generation and application methods were evaluated. Over the evaluated solutions and mixtures coating paste and CMC did not foam well. Latex and PVA solutions were foamable and the best solution for foam use was starch. PVA and casein can be used as foaming agents, but the best results were achieved with sodium dodecyl sulphate (SDS). SDS works well with starch solutions producing fine and stable foam. Foaming was done with simple mixers where pressurized air was fed to the solution. The foaming works fine when enough shear force is used together with sufficient foaming agent concentration. Foam application with curtain, rod and cylinder methods with a gap between the application device and paper were not usable because of high coating amount. Coating amounts were smallest with the blade method which achieved 0.9 g/m2 starch layer. Although some strength decrease was expected because of the foaming agent, it dit not have significant effect. The targeted coating amount of 0.5 g/m2 was not achieved due to the limitations with the methods. More precise foam application methods are needed. Continuous foam generation and feed to the paper surface with controllable device such as application teeth could improve the results.

Finnair Technical Procurement’s Processes and Service Quality

As primary objective, this thesis examines Finnair Technical Procurement’s service quality with its underlying process. As an internal unit, Technical Procurement serves as a link between external suppliers and internal customers. It is argued that external service quality requires a certain quality level within an organization. At the same time, aircraft maintenance business is subject to economic restraints. Therefore, a methodology was developed with a modified House of Quality that assists management in analyzing and evaluating Technical Procurement’s service level and connected process steps. It could be shown that qualitative and quantitative objectives do not exclude each other per se.

Evaluation of the dioxin and furan formation thermodynamics in combustion processes of urban solid wastes

Specific combustion programs (Gaseq, Chemical equilibria in perfect gases, Chris Morley) are used to model dioxin and formation in the incineration processes of urban solid wastes. Thanks to these programs, it is possible to establish correlations with the formation mechanisms postulated in literature on the subject. It was found that minimum oxygen quantities are required to obtain a significant formation of these compounds and that more furans than dioxins are formed. Likewise, dioxin and furan formation is related to the presence of carbon monoxide, and dioxin and furan distribution among its different compounds depends on the chlorine and hydrogen relative composition. This is due to the fact that an increased chlorine availability leads to the formation of compounds bearing a higher chlorine concentration (penta-, hexa-, hepta-, and octachlorides), whereas an increased hydrogen availability leads to the formation of compounds bearing a lower chlorine number (mono, di-, tri-, and tetrachlorides).

Granulation tissue formation -The effect of hydroxyapatite coating of cellulose on cellular differentiation

Haavan jyväiskudoksen muodostuminen – Hydroksiapatiittipinnoi-tetun selluloosasienen vaikutus solujen erilaistumiseen paranemisprosessin aikana Etsittäessä uusia luun bioyhteensopivia täytemateriaaleja selluloosasieni päällystettiin luun koostumusta muistuttavalla runsaasti piitä sisältävällä hydroksiapatiittikerroksella. Vastoin odotuksia hydroksiapatiittipinnoitettu selluloosa ei parantanut luun kasvua, vaan päinvastoin ylläpiti tulehdusta ja sidekudossolujen hakeutumista vamma-alueelle. Ihon alle implantoituna sama sienimateriaali edisti merkittävästi haavan verekkään jyväiskudoksen kasvua. Tämän löydöksen perusteella hydroksiapatiittipinnoitetun selluloosasienen vaikutusta haavan soluihin paranemisprosessin aikana tutkittiin tarkemmin ja havaittiin, että tulehdussolujen lisäksi sieniin kertyi tavallista enemmän sekä hematopoieettisia että mesenkymaalisia kantasoluja. Hematopoieettiset kantasolut sijaitsevat luuytimessä lähellä luun sisäpintaa. Luun hydroksiapatiitista vapautuu kalsiumioneja luun jatkuvan fysiologisen uudismuodostuksen ja hajottamisen yhteydessä. Kantasolut etsiytyvät luuytimeen kalsiumia aistivien reseptorien välityksellä. Koska luun pintakerrosta muistuttavasta hydroksiapatiittipinnoitteesta vapautuu kalsiumia, tämän ajateltiin toimivan selityksenä sille, että hematopoieettiset kantasolut hakeutuvat runsaslukuisesti juuri hydroksiapatiittipinnoitettuihin selluloosasieniin. Tämän hypoteesin mukaisesti hydroksiapatiittipinnoitettujen selluloosapalkkien läheisyydestä löydettiin suuria määriä kalsiumreseptoreja sisältäviä soluja. Jatkotutkimuksissa todettiin lisäksi, että hematopoieettiset kantasolut pystyivät sienissä erilaistumaan hemoglobiinia tuottaviksi soluiksi. Havaittujen punasolulinjan merkkiaineiden perusteella näyttäisikin siltä, että haavan paranemiskudoksessa tapahtuu paranemisen aikana ekstramedullaarista erytropoieesia. Nämä soluja ohjaavat vaikutukset saattavat olla hyödyllisiä vaikeasti paranevien haavojen hoidossa.

Microscopic simulation of pigment coating consolidation

The control of coating layer properties is becoming increasingly important as a result of an emerging demand for novel coated paper-based products and an increasing popularity of new coating application methods. The governing mechanisms of microstructure formation dynamics during consolidation and drying are nevertheless, still poorly understood. Some of the difficulties encountered by experimental methods can be overcome by the utilisation of numerical modelling and simulation-based studies of the consolidation process. The objective of this study was to improve the fundamental understanding of pigment coating consolidation and structure formation mechanisms taking place on the microscopic level. Furthermore, it is aimed to relate the impact of process and suspension properties to the microstructure of the coating layer. A mathematical model based on a modified Stokesian dynamics particle simulation technique was developed and applied in several studies of consolidation-related phenomena. The model includes particle-particle and particle-boundary hydrodynamics, colloidal interactions, Born repulsion, and a steric repulsion model. The Brownian motion and a free surface model were incorporated to enable the specific investigation of consolidation and drying. Filter cake stability was simulated in various particle systems, and subjected to a range of base substrate absorption rates and system temperatures. The stability of the filter cake was primarily affected by the absorption rate and size of particles. Temperature was also shown to have an influence. The consolidation of polydisperse systems, with varying wet coating thicknesses, was studied using imposed pilot trial and model-based drying conditions. The results show that drying methods have a clear influence on the microstructure development, on small particle distributions in the coating layer and also on the mobility of particles during consolidation. It is concluded that colloidal properties can significantly impact coating layer shrinkage as well as the internal solids concentration profile. Visualisations of particle system development in time and comparison of systems at different conditions are useful in illustrating coating layer structure formation mechanisms. The results aid in understanding the underlying mechanisms of pigment coating layer consolidation. Guidance is given regarding the relationship between coating process conditions and internal coating slurry properties and their effects on the microstructure of the coating.

Understanding change processes in business networks : a study of convergence in Finnish telecommunications 1985-2005

Aktörer inom telekommunikationsbranschen i Finland har genomgått en intensiv förändring under de senaste 25 åren, från 1980-talets självständiga företag till företag beroende av varandra, och även av aktörer inom närliggande branscher. I dag skapas telekommunikationsmarknaden inte endast av operatörerna, utan också av mediebolag (t.ex. MTV Media) och IT-företag (t.ex. TietoEnator). Gränserna mellan olika industrier håller därmed på att suddas ut - ett fenomen som allmänt benämns som teknologisk konvergens. Konvergens innebär att någonting integreras; det kan handla om t.ex. teknologier (telefoni och Internet), företag (AOL och Time Warner), industrier (telekom, media och IT-branscherna), tjänster (mobilt TV), produkter (PDA) osv. Detta innebär att ytterst få telekomaktörer ensamma kan vidareutveckla marknaden och tekniska lösningar. Samarbete mellan aktörer krävs; mobiltelefontillverkare, innehållsproducenter, operatörer osv. bör intesifiera sitt samarbete för att kunna erbjuda attraktiva tjänster och produkter till kunder och slutanvändare. Avhandlingen fokuserar speciellt på affärsnätverk och samarbetsmönster mellan nätverksaktörer som medel för att få tillgång till resurser som krävs i en konvergenskarakteriserad affärsomgivning. Avhandlingen lyfter fram vad den teknologiska konvergensen har inneburit för telekomaktörer, dvs. att företag tvingats förändra sina strategier och verksamhetsmodeller. För många företag i branschen har anpassningen till konvergenstänkande varit utmanande, och i vissa fall kan man till och med tala om att företagen upplevt en identitetskris. Den utförda forskningen visar att konvergens uppfattas på marknaden som en pågående förändringsprocess, där varje telekomaktör är tvungen att utvärdera sin roll och position i relation till andra aktörer inom branschen. Konvergensprocesser forsätter i framtiden med ökad intensitet. Aktörerna skapar medvetet sin omgivning genom att agera i olika roller, som kan sträcka sig över industrigränser. Avhandlingen påvisar även att externa händelser och industrikontexten påverkar dynamiken i ett affärsnätverk.

Usability of laser–arc hybrid welding processes in industrial applications

Metal industries producing thick sections have shown increasing interest in the laser–arc hybrid welding process because of its clear advantages compared with the individual processes of autogenous laser welding and arc welding. One major benefit of laser–arc hybrid welding is that joints with larger gaps can be welded with acceptable quality compared to autogenous laser welding. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. The objective of this research is to present a parameter set-up for laser–arc hybrid welding processes, introduce a methodical comparison of the chosen parameters, and discuss how this technology may be adopted in industrial applications. The research describes the principles, means and applications of different types of laser–arc hybrid welding processes. Conducted experiment processing variables are presented and compared using an analytical model which can also be used for predictive simulations. The main argument in this thesis is that profound understanding of the advanced technology of laser-arc hybrid welding will help improve the productivity of welding in industrial applications. Based on a review of the current knowledge base, important areas for further research are also identified. This thesis consists of two parts. The first part introduces the research topic and discusses laser–arc hybrid welding by characterizing its mechanism and most important variables. The second part comprises four research papers elaborating on the performance of laser– arc hybrid welding in the joining of metals. The study uses quantitative and qualitative research methods which include in-depth, interpretive analyses of results from a number of research groups. In the interpretive analysis, the emphasis is placed on the relevance and usefulness of the investigative results drawn from other research publications. The results of this study contribute to research on laser–arc hybrid welding by increasing understanding of how old and new perspectives on laser–arc hybrid welding are evidenced in industry. The research methodology applied permits continued exploration of how laser–arc hybrid welding and various process factors influence the overall quality of the weld. Thestudy provides a good foundation for future research, creates improved awareness of the laser–arc hybrid welding process, and assists the metal industry to maximize welding productivity.

Measuring Processes of a New Packaging Solutions with the Balanced Scorecard, case DigiCup

The aim of this study was to create a Balanced Scorecard to the DigiCup solution. The first goal was to create process descriptions to the few critical processes. The second goal was to define appropriate measurements, according to customer survey as well as following the Balanced Scorecard process description, to manage the critical success factors. The overall goal of this study was to create a performance measurement system for the solution which guides the operation towards continuous improvement. This study was conducted by using both qualitative and quantitative methods, and the analysis was done by using a case study method. The material was gathered from the current customers, the management and the employees using structured, semi-structured and open group and individual interviews. The current customers were divided into retailers and direct customers of the DigiCup solution. The questions which the customers were asked were related to the information about interviewee, company, business strategy, market, satisfaction survey and future requirements. The management defined the strategy and took part in specifying the perspectives, objectives and measurements to the Balanced Scorecard of the DigiCup solution. The employees participated into the choosing of the metrics. The material consisted from altogether sixteen interviews. At the beginning of the study the product development, the order-delivery as well as the printing processes was chosen to be the critical processes of the DigiCup solution. These processes were concentrated on already in the literature review while trying to find the characteristics of these processes as well as the critical success factors and the appropriate measurements, which could be utilized when creating the Balanced Scorecard to the DigiCup solution according to the customer survey. The appropriate perspectives, objectives and measurements were found to the DigiCup solution. The chosen measures works as a basis for the development of IT-reporting tool. As a conclusion it can be stated that when discussing a new business, where the objectives are changing according to which development’s phases the company is in, the measurement should be updated often enough.

Hakun kulutusosien materiaalivaihtoehdot sellutehtaan puunkäsittelylaitoksen erilaisiin prosessiolosuhteisiin

Selluteollisuuden puunkäsittelylaitoksilla laitteiden kuluminen on prosessin luonteesta johtuen suurta ja kulumisen aiheuttamat kunnossapitokustannukset laitteiden elinkaaren aikana ovat huomattavia. Näissä olosuhteissa toimivan hakun osien kulumista on tutkittu ja tutkimusten pohjalta on kehitetty kulutusta kestäviä materiaalivaihtoehtoja. Vaihtoehtojen vertailut prosesseittain kuitenkin puuttuvat. Terävasteen osalta tutkimus- ja kehitystyötä on tehty vähän. Tässä diplomityössä selvitetään ja vertaillaan hakun kulutusosien kulumismekanismeja, osien materiaalivaihtoehtoja, valmistus- ja kunnostusmenetelmiä ja -kustannuksia laitteen elinkaaren aikana kolmessa erilaisessa puunkäsittelyprosessissa. Työssä annetaan suosituksia kuhunkin prosessiin ja kunnossapitostrategiaan parhaiten soveltuvista ratkaisuista. Työn Case-osuudessa tutkitaan uusia kulutusta kestäviä materiaalivaihtoehtoja terävasteelle. Case-tutkimuksen tuloksena löydettiin terävasteelle kolme uutta materiaalivaihtoehtoa sekä muita vaihtoehtoja, joiden käyttökelpoisuutta kannattaa tutkia lisää. Samalla saatiin terävasteelle parempaan laatuun pystyvä ja kilpailukykyisempi toimittaja. Tutkimuksen perusteella saatiin uusia suosituksia myös muiden kulutusosien materiaali- ja/tai pinnoitusvaihtoehdoiksi. Tuloksista voidaan mainita lisäksi, että kulutusosille löydettiin suositeltavimmat elinkaarikustannuksiltaan edullisimmat vaihtoehdot. Kulutusosien kunnostamiseen liittyen havaittiin, että kunnostaminen on kannattavaa yhtä poikkeusta lukuun ottamatta. Kunnostusprosessista löydettiin kehitettävää. Työn tuloksena saatiin myös useita uusia kehittämisideoita ja runsaasti suosituksia jatkotoimenpiteistä. Hakun kulutusosien nykytilasta saatiin hyvä käsitys ja kattava tietopaketti.

Evaluation of energy efficiency and best available techniques in pumping processes

The potential for enhancing the energy efficiency of industrial pumping processes is estimated to be in some cases up to 50 %. One way to define further this potential is to implement techniques in accordance to definition of best available techniques in pumping applications. These techniques are divided into three main categories: Design, control method & maintenance and distribution system. In the theory part of this thesis first the definition of best available techniques (BAT) and its applicability on pumping processes is issued. Next, the theory around pumping with different pump types is handled, the main stress being in centrifugal pumps. Other components needed in a pumping process are dealt by presenting different control methods, use of an electric motor, variable speed drive and the distribution system. Last part of the theory is about industrial pumping processes from water distribution, sewage water and power plant applications, some of which are used further on in the empirical part as example cases. For the empirical part of this study four case studies on typical pumping processes from older Master’s these were selected. Firstly the original results were analyzed by studying the distribution of energy consumption between different system components and using the definition of BAT in pumping, possible ways to improve energy efficiency were evaluated. The goal in this study was that by the achieved results it would be possible to identify the characteristic energy consumption of these and similar pumping processes. Through this data it would then be easier to focus energy efficiency actions where they might be the most applicable, both technically and economically.

Recovery and refining of manganese as by-product from hydrometallurgical processes

The consumption of manganese is increasing, but huge amounts of manganese still end up in waste in hydrometallurgical processes. The recovery of manganese from multi-metal solutions at low concentrations may not be economical. In addition, poor iron control typically prevents the production of high purity manganese. Separation of iron from manganese can be done with chemical precipitation or solvent extraction methods. Combined carbonate precipitation with air oxidation is a feasible method to separate iron and manganese due to the fast kinetics, good controllability and economical reagents. In addition the leaching of manganese carbonate is easier and less acid consuming than that of hydroxide or sulfide precipitates. Selective iron removal with great efficiency from MnSO4 solution is achieved by combined oxygen or air oxidation and CaCO3 precipitation at pH > 5.8 and at a redox potential of > 200 mV. In order to avoid gypsum formation, soda ash should be used instead of limestone. In such case, however, extra attention needs to be paid on the reagents mole ratios in order to avoid manganese coprecipitation. After iron removal, pure MnSO4 solution was obtained by solvent extraction using organophosphorus reagents, di-(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4- trimethylpentyl)phosphinic acid (CYANEX 272). The Mn/Ca and Mn/Mg selectivities can be increased by decreasing the temperature from the commonly used temperatures (40 –60oC) to 5oC. The extraction order of D2EHPA (Ca before Mn) at low temperature remains unchanged but the lowering of temperature causes an increase in viscosity and slower phase separation. Of these regents, CYANEX 272 is selective for Mn over Ca and, therefore, it would be the better choice if there is Ca present in solution. A three-stage Mn extraction followed by a two-stage scrubbing and two-stage sulfuric acid stripping is an effective method of producing a very pure MnSO4 intermediate solution for further processing. From the intermediate MnSO4 some special Mn- products for ion exchange applications were synthesized and studied. Three types of octahedrally coordinated manganese oxide materials as an alternative final product for manganese were chosen for synthesis: layer structured Nabirnessite, tunnel structured Mg-todorokite and K-kryptomelane. As an alternative source of pure MnSO4 intermediate, kryptomelane was synthesized by using a synthetic hydrometallurgical tailings. The results show that the studied OMS materials adsorb selectively Cu, Ni, Cd and K in the presence of Ca and Mg. It was also found that the exchange rates were reasonably high due to the small particle dimensions. Materials are stable in the studied conditions and their maximum Cu uptake capacity was 1.3 mmol/g. Competitive uptake of metals and acid was studied using equilibrium, batch kinetic and fixed-bed measurements. The experimental data was correlated with a dynamic model, which also accounts for the dissolution of the framework manganese. Manganese oxide micro-crystals were also bound onto silica to prepare a composite material having a particle size large enough to be used in column separation experiments. The MnOx/SiO2 ratio was found to affect significantly the properties of the composite. The higher the ratio, the lower is the specific surface area, the pore volume and the pore size. On the other hand, higher amount of silica binder gives composites better mechanical properties. Birnesite and todorokite can be aggregated successfully with colloidal silica at pH 4 and with MnO2/SiO2 weight ratio of 0.7. The best gelation and drying temperature was 110oC and sufficiently strong composites were obtained by additional heat-treatment at 250oC for 2 h. The results show that silica–supported MnO2 materials can be utilized to separate copper from nickel and cadmium. The behavior of the composites can be explained reasonably well with the presented model and the parameters estimated from the data of the unsupported oxides. The metal uptake capacities of the prepared materials were quite small. For example, the final copper loading was 0.14 mmol/gMnO2. According to the results the special MnO2 materials are potential for a specific environmental application to uptake harmful metal ions.