Towards the Best A++ Rating Productivity of Research and Teaching in Finnish Universities

Tämän tutkimusraportin suomenkielinen versio on osoitteessa: http://urn.fi/URN:ISBN:978-951-29-4509-2

Switching components for medium voltage drives

Nowadays power drives are the essential part almost of all technological processes. Improvement of efficiency and reduction of losses require development of semiconductor switches. It has a particular meaning for the constantly growing market of renewable sources, especially for wind turbines, which demand more powerful semiconductor devices for control with growth of power. Also at present semiconductor switches are the key component in energy transmission, optimization of generation and network connection. The aim of this thesis is to make a survey of contemporary semiconductor components, showing difference in structures, advantages, disadvantages and most suitable applications. There is topical information about voltage, frequency and current limits of different switches. Study tries to compare dimensions and price of different components. Main manufacturers of semiconductor components are presented with the review of devices produced by them, and a conclusion about their availability was made. IGBT is selected as a main component in this study, because nowadays it is the most attractive component for usage in power drives, especially at the low levels of medium voltage. History of development of IGBT structure, static and dynamic characteristics are considered. Thesis tells about assemblies and connection of components and problems which can appear. One of key questions about semiconductor materials and their future development was considered. For the purpose of comparison strong and weak sides of different switches, calculation of losses of IGBT and its basic competitor – IGCT is presented. This master’s thesis makes an effort to answer the question if there are at present possibilities of accurate selection of switches for electrical drives of different rates of power and looks at future possible ways of development of semiconductor market.

Combining Productivity and Renewal in a Production Organization: a Case Study on Organizational Ambidexterity

This case study examined how productivity and renewal are combined in a production organization operating in process industry through the antecedents of organizational ambidexterity; structure, culture, and management. The empirical material consisted of semi-structured interviews, observations and case organization documents. The findings suggest that the case organization structurally separates exploitation and exploration to separate units. However, it was found that the units focusing on exploration also devote resources to exploitation. External networks, such as customers, suppliers, and other factories seemed to play a role in the exploration activities, as well as in learning activities, which were connected to renewal. Productivity was seen as a natural part of a production organization and pursued at manufacturing units. Process management techniques appeared to be spread across the organization and having positive impact on exploitation and negative impact on exploration. The managerial culture and management’s capability to communicate goals, vision and strategy was found to be unsatisfactory. This thesis contributes to the new research paradigm of organizational ambidexterity by providing unique results on how the antecedents of organizational ambidexterity are accomplished in a production organization. Furthermore, the thesis extends the previous research of organizational renewal capability by connecting it to the ambidexterity theory.

The Productivity, Economy and Quality of Welding in the Different Geographical Areas of China - Today and in the Future

This master’s thesis gives out the real situation of the China welding industry and factories nowadays in different geographical areas, in order to inform the Finnish companies who have the willing to find a Chinese welding subcontractor a proper and correct selection concept by analyzing and supplying the information of different scale and form welding factories in different Chinese areas. The first section of this thesis gives out the general situation about the co-operation between China and Finland in the welding industry, also includes the general introduction of the Chinese welding industry. The second section gives out the geographical compartmentalization result of Chinese welding industry, which is where and how many areas will be studied in this thesis. The main body of this thesis is the real information of welding productivity, welding cost, and welding quality in China. All the information was collected from real factories in China by the author. The last section of this thesis is the improvements to the Chinese welding factories that have the willing to become a subcontractor, and the suggestions to the Finnish companies who may find a Chinese welding factory as their subcontractor in future.

Automatisointiin ja monistettavuuteen perustuvan palvelumallin soveltaminen tietojärjestelmätoimituksissa

Ohjelmistotuotannon yleinen ongelma on se, että toimitusprojektien läpivientiajat pitkittyvät. Kilpailun kiristyessä ohjelmistoalalla on alettu kiinnittää erityistä huomiota projektien eri vaiheiden tehostamiseen. Process Vision Oy kehittää energiatietojärjestelmiä Suomen energia-alan yrityksille. Yrityksessä on kehitetty vuonna 2010 palvelumalli, jonka avulla pyritään nopeuttamaan toimitusprojektien eri vaiheita. Valtioneuvosto valmisteli vuonna 2009 tuntimittausasetuksen, joka määritti sääntöjä mittaustiedon hallintaan energia-alalla. Kyseisen asetuksen pohjalta Energiateollisuus julkaisi vuonna 2010 ohjeistuksen, joka selkeyttää asetuksen sisällön vaatimuksia jakeluverkonhaltijoille ja sähkön myyjille. Process Vision Oy on valmistellut ohjeistuksen pohjalta tuntimittauspaketin, joka sisältää ohjeistuksen mukaiset toiminnot GENERIS-järjestelmässä. Tässä diplomityössä määritellään Process Vision Oy:n palvelumallin mukaiset standardikomponentit tuntimittauspaketin toimitusprojekteja varten. Työn tavoitteena on kehittää mahdollisimman pitkälle tuotteistettu tuntimittauspaketin toimitus uusille ja vanhoille asiakkaille. Työn lopussa pohditaan miten hyvin palvelumalli soveltuu tuntimittauspaketin toimitusprojekteihin. Lisäksi työssä kartoitetaan yrityksessä käytössä olevien automatisointityökalujen kehitystarpeita. Työn tuloksena saatiin määriteltyä GENERIS-objektit ja konfiguraatiot, jotka toimitetaan tuntimittauspaketin mukana. Työn ohessa sisällytettiin yrityksen Suomen taseselvitysjärjestelmien asennusohjeeseen tuntimittauspaketin toiminnallisuuksien konfigurointi. Uusien vientimäärittelyjen avulla voidaan tuntimittauspaketin toiminnallisuudet toimittaa jatkossa tehokkaammin kuin aiemmin.

Identification of Some Additional Loss Components in High-Power Low-Voltage Permanent Magnet Generators

Permanent magnet generators (PMG) represent the cutting edge technology in modern wind mills. The efficiency remains high (over 90%) at partial loads. To improve the machine efficiency even further, every aspect of machine losses has to be analyzed. Additional losses are often given as a certain percentage without providing any detailed information about the actual calculation process; meanwhile, there are many design-dependent losses that have an effect on the total amount of additional losses and that have to be taken into consideration. Additional losses are most often eddy current losses in different parts of the machine. These losses are usually difficult to calculate in the design process. In this doctoral thesis, some additional losses are identified and modeled. Further, suggestions on how to minimize the losses are given. Iron losses can differ significantly between the measured no-load values and the loss values under load. In addition, with embedded magnet rotors, the quadrature-axis armature reaction adds losses to the stator iron by manipulating the harmonic content of the flux. It was, therefore, re-evaluated that in salient pole machines, to minimize the losses and the loss difference between the no-load and load operation, the flux density has to be kept below 1.5 T in the stator yoke, which is the traditional guideline for machine designers. Eddy current losses may occur in the end-winding area and in the support structure of the machine, that is, in the finger plate and the clamping ring. With construction steel, these losses account for 0.08% of the input power of the machine. These losses can be reduced almost to zero by using nonmagnetic stainless steel. In addition, the machine housing may be subjected to eddy current losses if the flux density exceeds 1.5 T in the stator yoke. Winding losses can rise rapidly when high frequencies and 10–15 mm high conductors are used. In general, minimizing the winding losses is simple. For example, it can be done by dividing the conductor into transposed subconductors. However, this comes with the expense of an increase in the DC resistance. In the doctoral thesis, a new method is presented to minimize the winding losses by applying a litz wire with noninsulated strands. The construction is the same as in a normal litz wire but the insulation between the subconductors has been left out. The idea is that the connection is kept weak to prevent harmful eddy currents from flowing. Moreover, the analytical solution for calculating the AC resistance factor of the litz-wire is supplemented by including an end-winding resistance in the analytical solution. A simple measurement device is developed to measure the AC resistance in the windings. In the case of a litz-wire with originally noninsulated strands, vacuum pressure impregnation (VPI) is used to insulate the subconductors. In one of the two cases studied, the VPI affected the AC resistance factor, but in the other case, it did not have any effect. However, more research is needed to determine the effect of the VPI on litz-wire with noninsulated strands. An empirical model is developed to calculate the AC resistance factor of a single-layer formwound winding. The model includes the end-winding length and the number of strands and turns. The end winding includes the circulating current (eddy currents that are traveling through the whole winding between parallel strands) and the main current. The end-winding length also affects the total AC resistance factor.

The pH-dependent phase distribution of wood pitch components in papermaking processes

Wood contains only a very small amount of lipophilic extractives, commonly known as wood pitch. The pitch is known to cause severe problems in papermaking processes. The amount of pitch in process waters can be decreased by seasoning of the raw material prior to pulping, pulp washing, removal of pitch by flotation, adsorption of pitch onto various mineral surfaces, and retention of pitch to the fibre material by cationic polymers. The aim of this study was to determine the influence of pH on some of the methods used for pitch control. Experiments were performed using laboratory-made wood pitch emulsions with varying pH, salt concentration, hemicellulose concentration and pitch composition. These emulsions were used to study the phase distribution of resin and fatty acids, the colloidal stability of pitch with and without steric stabilisation by galactoglucomannans, and the interactions between wood pitch and mineral particles. Purification of unbleached and peroxidebleached mill process water was performed by froth flotation in combination with a foaming agent. The distribution of resin and fatty acids (RFAs) between colloidal pitch droplets and the water phase was very dependent on pH. At pH 3, almost all of the RFAs were attached to the pitch droplets, while increasing the pH led to increasing concentration of dissolved RFAs in the water phase. The presence of salt shifted the release of RFAs towards higher pH, while lower ratio of neutral pitch in the emulsion resulted in release of RFAs at lower pH. It was also seen that the dissolution and adsorption of RFAs at sudden pHchanges takes place very quickly. Colloidal pitch was more stable against electrolyte-induced aggregation at higher pH, due to its higher anionic charge. The concentration of cationic polymers needed to aggregate colloidal pitch also increased with increasing pH. The surface characteristics of solid particles, such as amount of charged groups, were very important for understanding their interactions with colloidal wood pitch. Water-soluble galactoglucomannans stabilised the colloidal pitch sterically against aggregation, but could not completely prevent interactions between wood pitch and hydrophilic particles. Froth flotation of unbleached and peroxidebleached process water showed that the pitch could be removed more effectively and selectively at low pH, compared to at neutral pH. The pitch was removed more effectively, using lower concentrations of foaming agent, from peroxide-bleached water than from unbleached water. The results show that pH has a major impact on various pulping and papermaking processes. It determines the anionic charge of the colloidal pitch and the solubility of certain pitch components. Because of this, the pH influences the effectiveness of pitch retention and removal of pitch. The results indicate that pitch problems could be diminished by acknowledging the importance of pH in various papermaking processes.

Productivity and Services – Safety Telephone Services for the Elderly

Previous research on productivity is often associated with manufacturing or uses manufacturing definitions of productivity. Marketing research on services has not been satisfied with the manufacturing definitions. No universal definition for service productivity exists. The lack of a universal definition highlights the complexity entailed in the concept of productivity. The objective of this study was to investigate service productivity in situations, where traditional ways are in some cases even not possible or are not enough. In one definition of the productivity of service organisations there is the efficiency of the organisation on the input side and on the output side the customers’ perceived quality or value-in-use. To learn about value-in-use, many methods have been developed. A common practice is to make customer opinion surveys in the form of customer questionnaires and interviews. However, customers cannot always be asked directly, for example, because of impaired cognitive abilities. Such cases include the elderly and children. Furthermore, customer opinion surveys are time consuming. In addition, customers do not always know what kind of services they would benefit from. For the empirical part of the study, a business area was identified where traditional ways of measuring value-in-use are difficult or in some cases even not possible. This business area is safety telephone services. These services are most often used by the elderly. The way to define value-in-use here was to assess how well the services offered met customer expectations. Comparing the services customers asked for and the services provided to them indicated whether customer expectations were met. This study showed that customers had their ideas concerning the contents of the services but many times the services provided did not meet these expectations. Organisational efficiency aspirations can decrease customers’ value-in-use. This study found a solution, in which increasing organisational efficiency would go hand-in-hand with increasing customers’ value-in-use; the result being that the organisations’ needs and the service users’ expectations were in line. Value creation for customers produced organisational efficiency and thus increased productivity. In this study, customer expectations were observed by means of wellness technology. With the help of modern technology, customer expectations can be followed quickly and easily and customers can co-create with the organisation. This type of an approach could be useful even in the development of other services for other ages and in different contexts. If a service organisation decreases the number of personnel and, at the same time, tries to offer services to the same or a larger clientele, customers easily notice the change, which is often negative. To avoid harmful decrease in value-in-use, limitations to the aspiration of efficiency should be implemented – one of such is that the organisation is required to meet certain quality standards defined by experts. The aim is to secure that, as a result of efficiency aspirations in the organisation, the quality of the service offerings does not diminish below mutually agreed standards. Traditionally, when productivity in services has been estimated, organisational efficiency has not been combined with both customer expectations and an expert assessment of quality. This study contributes with novel thinking entitled ‘Relationship Management of the Elderly’. This study handles productivity, expert defined quality and value-in-use in an organisational context, which is practically untouched in previous research studies.

Hitsaustuotannon kehittäminen tuulivoimalan tornin valmistuksessa

Tuulivoima on Euroopassa nopeimmin kasvava energian tuotantomuoto. Tuulivoimateollisuuden arvioidaan kasvavan Suomessa huomattavasti lähivuosien aikana ennakoidun syöttötariffipäätöksen myötä, jolloin kilpailu alalla tulee kasvamaan. Tavoitteena oli kehittää tuulivoimalan tornin valmistusta Levator Oy:ssä hitsaustuotantoa tehostamalla ja tuotannon ohjattavuutta parantamalla. Kehitystyöhön kuului toisen hitsauslinjan käyttöönoton suunnittelu ja ohjeiston laatiminen työnjohdolle. Toisen hitsauslinjan käyttöönoton suunnittelun tarkoituksena oli suunnitella muutokset nykyiseen tuotantoon uuden linjan käyttöönoton mahdollistamiseksi. Suunnittelu aloitettiin valitsemalla hitsausprosessit, jonka jälkeen suunniteltiin laitetarpeet työvaihe-analyysien pohjalta. Tuotantolayout muutettiin nykyisestä funktionaalisesta tuotannosta tuotantosoluista koostuvaksi tuotantolinjaksi, jolloin materiaalien virtautus parani huomattavasti. Tuotannon ohjaustavaksi valittiin kapeikko-ohjaus. Ohjeiston laatimisen tarkoituksena oli kerätä ja dokumentoida kaikki tuotannossa tarvittava tieto. Ohjeiston sisältää laadunohjaus, materiaalivirtojen ohjaus ja työnohjaus osiot, joiden tarkoituksena on helpottaa työnjohtamista. Ohjeisto määrittelee yhtenäiset tuotannon toimintatavat, jolloin tuotannon ohjattavuus helpottuu. Tavoitteet täyttyivät, kun toisen tuotantolinjan käyttöönoton vaatimat muutokset aloitettiin suunnitelmien mukaisesti syyskuussa 2009. Ohjeiston sisältö saatiin määriteltyä ja eri osioiden pilotit saatiin valmiiksi joulukuun aikana. Tuotannon ohjattavuus kehittyi huomattavasti ja samalla tuottavuus parani merkittävästi.

Chromatographic recovery of chemicals from acidic biomass hydrolysates

Lignocellulosic biomasses (e.g., wood and straws) are a potential renewable source for the production of a wide variety of chemicals that could be used to replace those currently produced by petrochemical industry. This would lead to lower greenhouse gas emissions and waste amounts, and to economical savings. There are many possible pathways available for the manufacturing of chemicals from lignocellulosic biomasses. One option is to hydrolyze the cellulose and hemicelluloses of these biomasses into monosaccharides using concentrated sulfuric acid as catalyst. This process is an efficient method for producing monosaccharides which are valuable platforn chemicals. Also other valuable products are formed in the hydrolysis. Unfortunately, the concentrated acid hydrolysis has been deemed unfeasible mainly due to high chemical consumption resulting from the need to remove sulfuric acid from the obtained hydrolysates prior to the downstream processing of the monosaccharides. Traditionally, this has been done by neutralization with lime. This, however, results in high chemical consumption. In addition, the by-products formed in the hydrolysis are not removed and may, thus, hinder the monosaccharide processing. In order to improve the feasibility of the concentrated acid hydrolysis, the chemical consumption should be decreased by recycling of sulfuric acid without neutralization. Furthermore, the monosaccharides and the other products formed in the hydrolysis should be recovered selectively for efficient downstream processing. The selective recovery of the hydrolysis by-products would have additional economical benefits on the process due to their high value. In this work, the use of chromatographic fractionation for the recycling of sulfuric acid and the selective recovery of the main components from the hydrolysates formed in the concentrated acid hydrolysis was investigated. Chromatographic fractionation based on the electrolyte exclusion with gel type strong acid cation exchange resins in acid (H+) form as a stationary phase was studied. A systematic experimental and model-based study regarding the separation task at hand was conducted. The phenomena affecting the separation were determined and their effects elucidated. Mathematical models that take accurately into account these phenomena were derived and used in the simulation of the fractionation process. The main components of the concentrated acid hydrolysates (sulfuric acid, monosaccharides, and acetic acid) were included into this model. Performance of the fractionation process was investigated experimentally and by simulations. Use of different process options was also studied. Sulfuric acid was found to have a significant co-operative effect on the sorption of the other components. This brings about interesting and beneficial effects in the column operations. It is especially beneficial for the separation of sulfuric acid and the monosaccharides. Two different approaches for the modelling of the sorption equilibria were investigated in this work: a simple empirical approach and a thermodynamically consistent approach (the Adsorbed Solution theory). Accurate modelling of the phenomena observed in this work was found to be possible using the simple empirical models. The use of the Adsorbed Solution theory is complicated by the nature of the theory and the complexity of the studied system. In addition to the sorption models, a dynamic column model that takes into account the volume changes of the gel type resins as changing resin bed porosity was also derived. Using the chromatography, all the main components of the hydrolysates can be recovered selectively, and the sulfuric acid consumption of the hydrolysis process can be lowered considerably. Investigation of the performance of the chromatographic fractionation showed that the highest separation efficiency in this separation task is obtained with a gel type resin with a high crosslinking degree (8 wt. %); especially when the hydrolysates contain high amounts of acetic acid. In addition, the concentrated acid hydrolysis should be done with as low sulfuric acid concentration as possible to obtain good separation performance. The column loading and flow rate also have large effects on the performance. In this work, it was demonstrated that when recycling of the fractions obtained in the chromatographic fractionation are recycled to preceding unit operations these unit operations should included in the performance evaluation of the fractionation. When this was done, the separation performance and the feasibility of the concentrated acid hydrolysis process were found to improve considerably. Use of multi-column chromatographic fractionation processes, the Japan Organo process and the Multi-Column Recycling Chromatography process, was also investigated. In the studied case, neither of these processes could compete with the single-column batch process in the productivity. However, due to internal recycling steps, the Multi-Column Recycling Chromatography was found to be superior to the batch process when the product yield and the eluent consumption were taken into account.

Quality, Productivity and Economy in Welding Manufacturing - Case Study: West Africa

This thesis studies quality, productivity and economy in welding manufacturing in West African states such as Ghana, Nigeria and Cameroon. The study consists of two parts: the first part, which forms the theoretical background, reviews relevant literature concerning the metal and welding industries, and measurement of welding quality, productivity and economy. The second part, which is the empirical part, aims to identify activities in the metal manufacturing industries where welding is extensively used and to determine the extent of welding quality, productivity and economy measurements in companies operating in the metal manufacturing industries. Additionally, the thesis aims to identify challenges that companies face and to assess the feasibility of creating a network to address these issues. The research methods used in the empirical part are the case study (qualitative) method and the survey (quantitative) method. However, the case study method was used to elicit information from companies in Ghana, while the survey method was used to elicit information from companies in Nigeria and Cameroon. The study considers important areas that contribute to creating awareness and understanding of the current situation of the welding industry in West Africa. These areas include the metal manufacturing industrial sector, metal products manufactured, metal production and manufacturing systems deployed, welding quality, productivity and economy measurement systems utilized, equipment and materials on the markets, general challenges facing companies in welding operations, welding technology programs and research in local universities, and SWOT analysis of the various West African states. The notable findings indicate that majority of the companies operate in the constructionindustrial sector. Also, majority of the companies are project manufacturing oriented, thus provide services to customers operating in the growing industries such as the oil and gas, mining, food and the energy industry. In addition, only few companies are certified under standards such as ISO 9001, ISO 3834, and OHSAS 18001. More so, majority of the companies employ manual welding technique, and shielded metal arc welding (SMAW) as the commonly used welding process. Finally, welder salary is about € 300 / month as of June 2013 and the average operations turnover of medium to large companies is about € 5 million / year as at 2012. Based on analysis of the results of the study, it is noted that while welding activities are growing, the availability of cheap labor, the need for company and welder qualification and certification, and the need to manufacture innovative products through developmental projects (transfer of welding expertise and technology) remain as untapped opportunities in the welding industry in the West African states. The study serves as a solid platform for further research and concludes with several recommendations for development of the West African welding industry.

Employees’ continuous learning and job satisfaction - effects on productivity

In today’s knowledge intense economy the human capital is a source for competitive advantage for organizations. Continuous learning and sharing the knowledge within the organization are important to enhance and utilize this human capital in order to maximize the productivity. The new generation with different views and expectations of work is coming to work life giving its own characteristics on learning and sharing. Work should offer satisfaction so that the new generation employees would commit to organizations. At the same time organizations have to be able to focus on productivity to survive in the competitive market. The objective of this thesis is to construct a theory based framework of productivity, continuous learning and job satisfaction and further examine this framework and its applications in a global organization operating in process industry. Suggestions for future actions are presented for this case organization. The research is a qualitative case study and the empiric material was gathered by personal interviews concluding 15 employee and one supervisor interview. Results showed that more face to face interaction is needed between employees for learning because much of the knowledge of the process is tacit and so difficult to share in other ways. Offering these sharing possibilities can also impact positively to job satisfaction because they will increase the sense of community among employees which was found to be lacking. New employees demand more feedback to improve their learning and confidence. According to the literature continuous learning and job satisfaction have a relative strong relationship on productivity. The employee’s job description in the case organization has moved towards knowledge work due to continuous automation and expansion of the production process. This emphasizes the importance of continuous learning and means that productivity can be seen also from quality perspective. The normal productivity output in the case organization is stable and by focusing on the quality of work by improving continuous learning and job satisfaction the upsets in production can be handled and prevented more effectively. Continuous learning increases also the free human capital input and utilization of it and this can breed output increasing innovations that can increase productivity in long term. Also job satisfaction can increase productivity output in the end because employees will work more efficiently, not doing only the minimum tasks required. Satisfied employees are also found participating more in learning activities.

Thermal reactions of the major hydrocarbon components of biomass gasification gas

Gasification of biomass is an efficient method process to produce liquid fuels, heat and electricity. It is interesting especially for the Nordic countries, where raw material for the processes is readily available. The thermal reactions of light hydrocarbons are a major challenge for industrial applications. At elevated temperatures, light hydrocarbons react spontaneously to form higher molecular weight compounds. In this thesis, this phenomenon was studied by literature survey, experimental work and modeling effort. The literature survey revealed that the change in tar composition is likely caused by the kinetic entropy. The role of the surface material is deemed to be an important factor in the reactivity of the system. The experimental results were in accordance with previous publications on the subject. The novelty of the experimental work lies in the used time interval for measurements combined with an industrially relevant temperature interval. The aspects which are covered in the modeling include screening of possible numerical approaches, testing of optimization methods and kinetic modelling. No significant numerical issues were observed, so the used calculation routines are adequate for the task. Evolutionary algorithms gave a better performance combined with better fit than the conventional iterative methods such as Simplex and Levenberg-Marquardt methods. Three models were fitted on experimental data. The LLNL model was used as a reference model to which two other models were compared. A compact model which included all the observed species was developed. The parameter estimation performed on that model gave slightly impaired fit to experimental data than LLNL model, but the difference was barely significant. The third tested model concentrated on the decomposition of hydrocarbons and included a theoretical description of the formation of carbon layer on the reactor walls. The fit to experimental data was extremely good. Based on the simulation results and literature findings, it is likely that the surface coverage of carbonaceous deposits is a major factor in thermal reactions.