Laser cladding with scanning optics

Scanning optics create different types of phenomena and limitation to cladding process compared to cladding with static optics. This work concentrates on identifying and explaining the special features of laser cladding with scanning optics. Scanner optics changes cladding process energy input mechanics. Laser energy is introduced into the process through a relatively small laser spot which moves rapidly back and forth, distributing the energy to a relatively large area. The moving laser spot was noticed to cause dynamic movement in the melt pool. Due to different energy input mechanism scanner optic can make cladding process unstable if parameter selection is not done carefully. Especially laser beam intensity and scanning frequency have significant role in the process stability. The laser beam scanning frequency determines how long the laser beam affects with specific place local specific energy input. It was determined that if the scanning frequency in too low, under 40 Hz, scanned beam can start to vaporize material. The intensity in turn determines on how large package this energy is brought and if the intensity of the laser beam was too high, over 191 kW/cm2, laser beam started to vaporize material. If there was vapor formation noticed in the melt pool, the process starts to resample more laser alloying due to deep penetration of laser beam in to the substrate. Scanner optics enables more flexibility to the process than static optics. The numerical adjustment of scanning amplitude enables clad bead width adjustment. In turn scanner power modulation (where laser power is adjusted according to where the scanner is pointing) enables modification of clad bead cross-section geometry when laser power can be adjusted locally and thus affect how much laser beam melts material in each sector. Power modulation is also an important factor in terms of process stability. When a linear scanner is used, oscillating the scanning mirror causes a dwell time in scanning amplitude border area, where the scanning mirror changes the direction of movement. This can cause excessive energy input to this area which in turn can cause vaporization and process instability. This process instability can be avoided by decreasing energy in this region by power modulation. Powder feeding parameters have a significant role in terms of process stability. It was determined that with certain powder feeding parameter combinations powder cloud behavior became unstable, due to the vaporizing powder material in powder cloud. Mainly this was noticed, when either or both the scanning frequency or powder feeding gas flow was low or steep powder feeding angle was used. When powder material vaporization occurred, it created vapor flow, which prevented powder material to reach the melt pool and thus dilution increased. Also powder material vaporization was noticed to produce emission of light at wavelength range of visible light. This emission intensity was noticed to be correlated with the amount of vaporization in the powder cloud.

Susteinable steelmaking by process integration

Environmental issues, including global warming, have been serious challenges realized worldwide, and they have become particularly important for the iron and steel manufacturers during the last decades. Many sites has been shut down in developed countries due to environmental regulation and pollution prevention while a large number of production plants have been established in developing countries which has changed the economy of this business. Sustainable development is a concept, which today affects economic growth, environmental protection, and social progress in setting up the basis for future ecosystem. A sustainable headway may attempt to preserve natural resources, recycle and reuse materials, prevent pollution, enhance yield and increase profitability. To achieve these objectives numerous alternatives should be examined in the sustainable process design. Conventional engineering work cannot address all of these substitutes effectively and efficiently to find an optimal route of processing. A systematic framework is needed as a tool to guide designers to make decisions based on overall concepts of the system, identifying the key bottlenecks and opportunities, which lead to an optimal design and operation of the systems. Since the 1980s, researchers have made big efforts to develop tools for what today is referred to as Process Integration. Advanced mathematics has been used in simulation models to evaluate various available alternatives considering physical, economic and environmental constraints. Improvements on feed material and operation, competitive energy market, environmental restrictions and the role of Nordic steelworks as energy supplier (electricity and district heat) make a great motivation behind integration among industries toward more sustainable operation, which could increase the overall energy efficiency and decrease environmental impacts. In this study, through different steps a model is developed for primary steelmaking, with the Finnish steel sector as a reference, to evaluate future operation concepts of a steelmaking site regarding sustainability. The research started by potential study on increasing energy efficiency and carbon dioxide reduction due to integration of steelworks with chemical plants for possible utilization of available off-gases in the system as chemical products. These off-gases from blast furnace, basic oxygen furnace and coke oven furnace are mainly contained of carbon monoxide, carbon dioxide, hydrogen, nitrogen and partially methane (in coke oven gas) and have proportionally low heating value but are currently used as fuel within these industries. Nonlinear optimization technique is used to assess integration with methanol plant under novel blast furnace technologies and (partially) substitution of coal with other reducing agents and fuels such as heavy oil, natural gas and biomass in the system. Technical aspect of integration and its effect on blast furnace operation regardless of capital expenditure of new operational units are studied to evaluate feasibility of the idea behind the research. Later on the concept of polygeneration system added and a superstructure generated with alternative routes for off-gases pretreatment and further utilization on a polygeneration system producing electricity, district heat and methanol. (Vacuum) pressure swing adsorption, membrane technology and chemical absorption for gas separation; partial oxidation, carbon dioxide and steam methane reforming for methane gasification; gas and liquid phase methanol synthesis are the main alternative process units considered in the superstructure. Due to high degree of integration in process synthesis, and optimization techniques, equation oriented modeling is chosen as an alternative and effective strategy to previous sequential modelling for process analysis to investigate suggested superstructure. A mixed integer nonlinear programming is developed to study behavior of the integrated system under different economic and environmental scenarios. Net present value and specific carbon dioxide emission is taken to compare economic and environmental aspects of integrated system respectively for different fuel systems, alternative blast furnace reductants, implementation of new blast furnace technologies, and carbon dioxide emission penalties. Sensitivity analysis, carbon distribution and the effect of external seasonal energy demand is investigated with different optimization techniques. This tool can provide useful information concerning techno-environmental and economic aspects for decision-making and estimate optimal operational condition of current and future primary steelmaking under alternative scenarios. The results of the work have demonstrated that it is possible in the future to develop steelmaking towards more sustainable operation.

Supplier segmentation and development in project business

The purpose of this study was to expand the applicability of supplier segmentation and development approaches to the project-driven construction industry. These practices are less exploited and not well documented in this operational environment compared to the process-centric manufacturing industry. At first, portfolio models to supply base segmentation and various supplier development efforts were investigated in literature review. A step-wise framework was structured for the empirical research. The empirical study employed multiple research methods in three case studies in a large Finnish construction company. The first study categorized the construction item classes into the purchasing portfolio and positioned suppliers to the power matrix by investigating buyer-supplier relations. Using statistical tests, the study also identified factors that affect suppliers’ performance. The final case study identified improvement areas of the interface between a main contractor and one if its largest suppliers. The final results indicate that only by assessing the supply base in a holistic manner and the power circumstances in it, buyers comprehend how to best establish appropriate supplier development strategies in the project environment.

Maximizing of water recovery in nanofiltration of mine process waters by using antiscalants

Reverse osmosis and nanofiltration are among the most effective and widely used desalination and water softening technologies. They can also be used to treat mining wastewaters and are capable of producing water of extremely high purity, regardless of the high concentrations of toxic heavy metals and extreme pH and salinity. However, challenges with recovering the salts and metals from mining wastewaters in exploitable form, as well as problems with scaling still limit the process efficiency and the ratio of purified water recoverable from process waters. To address the problem of membrane scaling caused by calcium sulfate, batch filtration experiments with the Desal-5 DL nanofiltration membrane, three commercial antiscalants and actual mine process water from a copper mine were performed. The aim of these experiments was to find process conditions where maximum water recovery would be achieved before significant scaling or irreversible membrane fouling would occur and to further improve water recovery by addition of antiscalants. Water recovery of 70 % was reached with the experimental setups by optimizing process conditions. PC-504T antiscaling agent was determined to be the most effective of the three antiscalants used and the addition of 5 ppm of PC-504T allowed the water recovery to be further increased from 70 % to 85 % before major scaling was observed. In these conditions 92 % calcium rejection was achieved.

The collective dimension of freedom of religion or belief in international law : the application of findings to the case of Turkey

Pertinent domestic and international developments involving issues related to tensions affecting religious or belief communities have been increasingly occupying the international law agenda. Those who generate and, thus, shape international law jurisprudence are in the process of seeking some of the answers to these questions. Thus the need for reconceptualization of the right to freedom of religion or belief continues as demands to the right to freedom of religion or belief challenge the boundaries of religious freedom in national and international law. This thesis aims to contribute to the process of “re-conceptualization” by exploring the notion of the collective dimension of freedom of religion or belief with a view to advance the protection of the right to freedom of religion or belief. The case of Turkey provides a useful test case where both the domestic legislation can be assessed against international standards, while at the same time lessons can be drawn for the improvement of the standard of international review of the protection of the collective dimension of freedom of religion or belief. The right to freedom of religion or belief, as enshrined in international human rights documents, is unique in its formulation in that it provides protection for the enjoyment of the rights “in community with others”.1 It cannot be realized in isolation; it crosses categories of human rights with aspects that are individual, aspects that can be effectively realized only in an organized community of individuals and aspects that belong to the field of economic, social and cultural rights such as those related to religious or moral education. This study centers on two primary questions; first, what is the scope and nature of protection afforded to the collective dimension of freedom of religion or belief in international law, and, secondly, how does the protection of the collective dimension of freedom of religion or belief in Turkey compare and contrast to international standards? Section I explores and examines the notion of the collective dimension of freedom of religion or belief, and the scope of its protection in international law with particular reference to the right to acquire legal personality and autonomy religious/belief communities. In Section II, the case study on Turkey constitutes the applied part of the thesis; here, the protection of the collective dimension is assessed with a view to evaluate the compliance of Turkish legislation and practice with international norms as well as seeking to identify how the standard of international review of the collective dimension of freedom of religion or belief can be improved.

Hiilidioksidin käsittely P2G prosessia varten

Power-to-Gas (P2G) tarkoittaa sähköenergian muuttamista kaasuksi. Kyse on konseptista, jossa uusiutuvaa energiaa varastoidaan kaasuun kemialliseksi energiaksi. Siinä tuotettava kaasu on joko vetyä tai metaania. Metanoinnissa muodostetaan hiilidioksidista ja vedystä kemiallisella prosessilla metaania, joka voidaan syöttää maakaasuverkkoon. Hiilidioksidin laadulle tässä prosessissa ei ole selkeitä ohjeita. Tässä työssä on tavoitteena selvittää miten hiilidioksidin laatu vaikuttaa metanointiprosessiin ja miten sitä tulee käsitellä tätä prosessia varten. Selvitetään myös mahdollisia hiilidioksidinkäsittelymenetelmiä, sekä lyhyesti talteenotto- ja kuljetustapojen vaikutuksia niihin. Esitetään kirjallisuudesta löytyviä arvioita hiilidioksidin käsittelyn kustannuksille.

Modelling Cutting States in Rough Turning of 34CrNiMo6 Steel

Rough turning is an important form of manufacturing cylinder-symmetric parts. Thus far, increasing the level of automation in rough turning has included process monitoring methods or adaptive turning control methods that aim to keep the process conditions constant. However, in order to improve process safety, quality and efficiency, an adaptive turning control should be transformed into an intelligent machining system optimizing cutting values to match process conditions or to actively seek to improve process conditions. In this study, primary and secondary chatter and chip formation are studied to understand how to measure the effect of these phenomena to the process conditions and how to avoid undesired cutting conditions. The concept of cutting state is used to address the combination of these phenomena and the current use of the power capacity of the lathe. The measures to the phenomena are not developed based on physical measures, but instead, the severity of the measures is modelled against expert opinion. Based on the concept of cutting state, an expert system style fuzzy control system capable of optimizing the cutting process was created. Important aspects of the system include the capability to adapt to several cutting phenomena appearing at once, even if the said phenomena would potentially require conflicting control action.

Defining Sales and Operations Planning Process in an Environmental Management Company

Sales and operations research publications have increased significantly in the last decades. The concept of sales and operations planning (S&OP) has gained increased recognition and has been put forward as the area within Supply Chain Management (SCM). Development of S&OP is based on the need for determining future actions, both for sales and operations, since off-shoring, outsourcing, complex supply chains and extended lead times make challenges for responding to changes in the marketplace when they occur. Order intake of the case company has grown rapidly during the last years. Along with the growth, new challenges considering data management and information flow have arisen due to increasing customer orders. To manage these challenges, case company has implemented S&OP process, though initial process is in early stage and due to this, the process is not managing the increased customer orders adequately. Thesis objective is to explore extensively the S&OP process content of the case company and give further recommendations. Objectives are categorized into six different groups, to clarify the purpose of this thesis. Qualitative research methods used are active participant observation, qualitative interviews, enquiry, education, and a workshop. It is notable that demand planning was felt as cumbersome, so it is typically the biggest challenge in S&OP process. More proactive the sales forecasting can be, more expanded the time horizon of operational planning will turn out. S&OP process is 60 percent change management, 30 percent process development and 10 percent technology. The change management and continuous improvement can sometimes be arduous and set as secondary. It is important that different people are required to improve the process and the process is constantly evaluated. As well as, process governance is substantially in a central role and it has to be managed consciously. Generally, S&OP process was seen important and all the stakeholders were committed to the process. Particular sections were experienced more important than others, depending on the stakeholders’ point of views. Recommendations to objective groups are evaluated by the achievable benefit and resource requirement. The urgent and easily implemented improvement recommendations should be executed firstly. Next steps are to develop more coherent process structure and refine cost awareness. Afterwards demand planning, supply planning, and reporting should be developed more profoundly. For last, information technology system should be implemented to support the process phases.

Thick Section Laser Beam Welding of Structural Steels: Methods for Improving Welding Efficiency

Laser beam welding (LBW) is applicable for a wide range of industrial sectors and has a history of fifty years. However, it is considered an unusual method with applications typically limited to welding of thin sheet metal. With a new generation of high power lasers there has been a renewed interest in thick section LBW (also known as keyhole laser welding). There was a growing body of publications during 2001-2011 that indicates an increasing interest in laser welding for many industrial applications, and in last ten years, an increasing number of studies have examined the ways to increase the efficiency of the process. Expanding the thickness range and efficiency of LBW makes the process a possibility for industrial applications dealing with thick metal welding: shipbuilding, offshore structures, pipelines, power plants and other industries. The advantages provided by LBW, such as high process speed, high productivity, and low heat input, may revolutionize these industries and significantly reduce the process costs. The research to date has focused on either increasing the efficiency via optimizing process parameters, or on the process fundamentals, rather than on process and workpiece modifications. The argument of this thesis is that the efficiency of the laser beam process can be increased in a straightforward way in the workshop conditions. Throughout this dissertation, the term “efficiency” is used to refer to welding process efficiency, specifically, an increase in efficiency refers an increase in weld’s penetration depth without increasing laser power level or decreasing welding speed. These methods are: modifications of the workpiece – edge surface roughness and air gap between the joining plates; modification of the ambient conditions – local reduction of the pressure in the welding zone; modification of the welding process – preheating of the welding zone. Approaches to improve the efficiency are analyzed and compared both separately and combined. These experimentally proven methods confirm previous findings and contribute additional evidence which expand the opportunities for laser beam welding applications. The focus of this research was primarily on the effects of edge surface roughness preparation and pre-set air gap between the plates on weld quality and penetration depth. To date, there has been no reliable evidence that such modifications of the workpiece give a positive effect on the welding efficiency. Other methods were tested in combination with the two methods mentioned above. The most promising - combining with reduced pressure method - resulted in at least 100% increase in efficiency. The results of this thesis support the idea that joining those methods in one modified process will provide the modern engineering with a sufficient tool for many novel applications with potential benefits to a range of industries.

Climate change and global responsibility - the role of energy consumption, GDP and CO2 emissions

Climate change is one of the biggest challenges faced by this generation. Despite being the single most important environmental challenge facing the planet and despite over two decades of international climate negotiations, global greenhouse gas (GHG) emissions continue to rise. By the middle of this century, GHGs must be reduced by as much as 40-70% if dangerous climate change is to be avoided. In the Kyoto Protocol no quantitative emission limitation and reduction commitments were placed on the developing countries. For the planning of the future commitments period and possible participation of developing countries, information of the functioning of the energy systems, CO2 emissions development in different sectors, energy use and technological development in developing countries is essential. In addition to the per capita emissions, the efficiency of the energy system in relation to GHG emissions is crucial for the decision of future long-term burden sharing between countries. Country’s future development of CO2 emissions can be defined by the estimated CO2 intensity of the future and the estimated GDP growth. The changes in CO2 intensity depend on several factors, but generally developed countries’ intensity has been increasing in the industrialization phase and decreasing when their economy shifts more towards the system dominated by the service sector. The level of the CO2 intensity depends by a large extent on the production structure and the energy sources that are used. Currently one of the most urgent issues regarding global climate change is to decide the future of the Kyoto Protocol. Negotiations on this topic have already been initiated, with the aim of being finalised by the 2015. This thesis provides insights into the various approaches that can be used to characterise the concept of comparable efforts for developing countries in a future international climate agreement. The thesis examines the post-Kyoto burden sharing questions for developing countries using the contraction and convergence model, which is one approach that has been proposed to allocate commitments regarding future GHG emissions mitigation. This new approach is a practical tool for the evaluation of the Kyoto climate policy process and global climate change negotiations from the perspective of the developing countries.

Voimalaitoksen energiaraportoinnin kehittäminen

Diplomityössä tarkasteltiin Metsä Board Simpeleen voimalaitoksen energiaraportointi kokonaisuutta. Tarkastelun kohteena olivat lämpö-, sähkö- ja polttoaine-energiat. Tarkastelun pääpaino oli energian määritykseen tarvittavissa mittapisteissä sekä niistä muodostuvissa raporteissa. Työn tavoitteena oli saada luotettavat energiaraportit, jotka ovat jaoteltu selkeästi ja johdonmukaisesti. Tavoitteena oli myös vähentää kuukausiraportoinnin muodostamiseen tarvittavaa henkilötyöaikaa. Teoriaosuudessa käsitellään yleisesti voimalaitosprosessin toimintaa sekä siinä käytettäviä polttoaineita. Energiataseen muodostamisen perusteita tarkasteltiin voimalaitosprosessin kannalta. Energian määrityksiin käytettävät prosessimittaukset käytiin läpi. Raportointivelvollisuudet selvitettiin, niin tilastokeskuksien, kuin viranomaistenkin suuntaan. Työosuudessa perehdyttiin käytössä oleviin raportointikäytäntöihin sekä raporttipohjiin. Energialaskentayhtälöt ja parametrit tarkastettiin tarvittavilta osin. Työnaikana havaittiin nopeasti, että raportointi muodostetaan pitkälti Microsoft Excel-taulukkolaskentaohjelmiston avulla. Olemassa olevia automatisoituja raportteja ei hyödynnetty ollenkaan, koska niitä pidettiin epäluotettavina. Työn tuloksena automatisoidut kuukausiraportit tarkastettiin, virheet korjattiin ja ne otettiin käyttöön. Automaattisiin raportteihin tehtiin päivitysehdotukset uusista raporttipohjista. Viralliseen kuukausiraportointiin rakennettiin myös kokonaan uudet raportointipohjat, jotka hyödyntävät automaattisesti muodostuvia raportteja. Uudet raporttipohjat nopeuttivat raportointityötä merkittävästi. Polttoaine-energian hallintajärjestelmä todettiin vanhanaikaiseksi ja sen uusimista suositellaan. Uusinnalla raportointityö helpottuisi ja sen avulla siitä saataisiin kattavampi.

Increased profitability and efficiency by improving the Meetings & Events Category S2P-process – Case Company

The purpose of this research was to examine the most optimal way to arrange meetings and events management and source to pay –process in a global company. The research is a qualitative multi-method case study and is a commission from a global company. The theoretical framework of this research structures around two approaches. First approach focus on a purchasing strategy and management that shows the current role of procure-ment and introduce different ways to organize purchasing functions. Second approach focus on purchasing process management and improvement methods. Annual spend analyze, external and internal interviews and internal survey were done to gain compre-hensive knowledge about the current state of operations and possible solutions. Gathered data were then combined to theoretical framework in order to create optimal solution for the case company. Based on the research a source to pay –process and global policy for meeting and event category was created. The solution includes all relevant matters that are needed in order to secure efficient and profitable operations. The results show that optimal way to arrange meetings and events structures around standardized source to pay –processes, central-ized procurement, preferred supplier and clearly defined roles and responsibilities be-tween different stakeholders.

Barriers to Service-sector SME Internationalization in the EU Business Environment

The service sector in the global world is constantly growing: in Europe, they account currently approximately for 70 per cent of the total economy. Yet service internationalization is rather a new phenomenon: services have been traditionally seen as local entities, which also explains why research on service internationalization has properly begun only few decades ago. Even though the Single European Market allows free service movement between Member States, services do not move as actively as desired: approximately only one fifth of services are involved in cross-border trade. Therefore, the main purpose of this thesis is to analyze the barriers to service-sector SME internationalization in the EU business environment. To address the research purpose, the internationalization of service-sector SMEs in the EU area is first described and thereafter, the barriers to service-sector SME internationalization in the European context are mapped and analyzed from intra- and extra-firm perspectives. In order to understand the topic area and the phenomenon, a short glance is first taken into Europe as a business environment for service industries: the market characteristics and benefits of the common free trade area for service industries are described. Also earlier literature on service internationalization and barriers to international service trade are discussed. Due to low previous research activity on barriers specifically to international service trade, the discussion is improved by presenting general findings of barriers to SME internationalization. This research is conducted with qualitative methods: there is only a limited amount of previous research and qualitative methods provide a way of gathering in-depth information and reaching understanding from respondents’ perspectives. The evidence presented in the study was collected through six semi-structured interviews with six different small or medium sized international service firm representatives that all had the first-hand knowledge regarding their company’s process of delivering services from home market to other European countries. The results of the study provide a detailed description and analysis of intra- and extra-firm barriers to service-sector SME internationalization in the context of EU and indicate that in general, internal firm-specific barriers have a greater impact in determining firm’s possibilities to be engaged in cross-border service trade – external barriers played a smaller role. What might explain these results is that first of all, the study has full focus on service firms of smaller size and internal barriers tend to be particularly effective to SMEs as their resources, skills and capabilities are often limited, which limits internationalization possibilities. Second, the results may indicate that EU’s internal market and the free trade concept function quite well from service firms’ perspective, and the low service movement rate may be rather caused by firm’s own competences and resource-related difficulties than directly by flaws in the market. The results complete earlier literature and provide new and more detailed knowledge of barriers to cross-border service trade in the context of Europe. They also indicate that service internationalization should be observed separately from internationalization of traditional manufacturing firms due to unique service-specific characteristics. The findings of this study are particularly beneficial for small or medium sized service firm managers as it provides knowledge of delivering services across borders in Europe and of barriers that relate to that process.

Interactions of decision mechanisms in an entrepreneurial firm’s journey to become a major player in its industry

This study discusses the interactions of different decision-making mechanisms in the process of change of a successful entrepreneurial dairy firm in Vietnam. The purpose of the study is to construct a theoretical framework, which explains the interactions between effectual and causal decision-making processes in different phases of business, and to provide a real life example with practical recommendations for entrepreneurs and managers. In order to achieve this purpose, a preliminary theoretical framework was built, using process theories applied to different decision making modes, referred to as causation and effectuation. The case was studied through ethnographic research method, with three semi-structured interviews, one unstructured interview, secondary data and observations within four months in 2013-2014. After the data was analyzed, a modified framework was drawn from the result. The finding of this study shows that there was an interaction between effectual and causal decision-making processes in different stages of the company’s development. The entrepreneur applied effectual decision-making process to develop a unique business model and a new dairy market segment. However, when a new market demand arose, the company’s resources became insufficient, they thus had to shift to causation process to adapt to market change. Simultaneously, with better-accumulated resources, the entrepreneur continued the effectuation process to create another brand new dairy market segment. This study, thus, contributes to effectuation theory, emphasizing the necessity of combining effectual and causal decision-making processes in different phases of business. It is suggested that business would develop with an effectual process until a business model is viable for growth. It continues to use this process up to a certain degree. When the market changes, the company needs to collect more means to adapt to the changes. They need to set new goals and this is a shift to the use of causal process, which builds on prediction. It uses goals and teleology as driving mechanisms and tries to exploit and fill potential resource gaps to achieve these goals. At the same time, there are new iterations that look to establish new lines or types of business with the given means, which are now well established. This again employs effectual mechanisms, which are based on evolutionary process, until they reach the stage of viable tested business model. Moreover, this study hopes to provide know-how to entrepreneurs and managers of small companies in similar situations, suggesting how to combine effectual and causal decision-making processes to deal with various circumstances in different times.

Pour une constitutionnalisation du droit à la sécession au Canada

"Mémoire présenté à la Faculté des études supérieures en vue de l'obtention du grade de maîtrise en droit, option recherche (LL.M.)"