Competing tunneling and capacitive paths in Co-ZrO2 granular thin films

The ac electrical response is studied in thin films composed of well-defined nanometric Co particles embedded in an insulating ZrO2 matrix which tends to coat them, preventing the formation of aggregates. In the dielectric regime, ac transport originates from the competition between interparticle capacitive Cp and tunneling Rt channels, the latter being thermally assisted. This competition yields an absorption phenomenon at a characteristic frequency 1/(RtCp), which is observed in the range 1010 000 Hz. In this way, the effective ac properties mimic the universal response of disordered dielectric materials. Temperature and frequency determine the complexity and nature of the ac electrical paths, which have been successfully modeled by an Rt-Cp network.

Increasing Industrial Customer Value through the Internet in Transportation Services

Tutkimuksen tavoitteena oli selvittää, kuinka sähköisiä palveluita tarjoamalla voidaan tuottaa asiakkaalle lisäarvoa yritysten välisessä kaupankäynnissä. Tarkastelunäkökulmana oli kuljetuspalveluita tarjoava yritys. Teoreettinen tutkimus pohjautui palveluiden markkinointiin, erityisesti palvelun laatuun, asiakkaan kokeman arvon lisäämiseen, asiakkaan odotuksiin, sekä Internetin välityksellä käytävään sähköiseen kauppaan. Kyselytutkimuksella selvitettiin lähinnä asiakkaiden odotuksia, koska sähköisiä palveluita ei vielä ole laajalti käytössä. Tutkimuksen mukaan asiakkaat kokivat useimmat ehdotetuista palveluista, kuten ajantasaisen reitti- ja aikataulupalvelun, tarkan lähtö- ja tuloinformaation, sekä konttien seurantapalvelun, lisäarvoa tuoviksi. Toisaalta yrityksen tarjoama uutispalvelu, tavaroiden tullaus ja keskustelufoorumi sähköisessä muodossa eivät tuntuneet luovan asiakkaille lisäarvoa.

Position sensorless electrically excited synchronous motor drive for industrial use based on direct flux linkage and torque control

Synchronous machines with an AC converter are used mainly in large drives, for example in ship propulsion drives as well as in rolling mill drives in steel industry. These motors are used because of their high efficiency, high overload capacity and good performance in the field weakening area. Present day drives for electrically excited synchronous motors are equipped with position sensors. Most drives for electrically excited synchronous motors will be equipped with position sensors also in future. This kind of drives with good dynamics are mainly used in metal industry. Drives without a position sensor can be used e.g. in ship propulsion and in large pump and blower drives. Nowadays, these drives are equipped with a position sensor, too. The tendency is to avoid a position sensor if possible, since a sensor reduces the reliability of the drive and increases costs (latter is not very significant for large drives). A new control technique for a synchronous motor drive is a combination of the Direct Flux Linkage Control (DFLC) based on a voltage model and a supervising method (e.g. current model). This combination is called Direct Torque Control method (DTC). In the case of the position sensorless drive, the DTC can be implemented by using other supervising methods that keep the stator flux linkage origin centered. In this thesis, a method for the observation of the drift of the real stator flux linkage in the DTC drive is introduced. It is also shown how this method can be used as a supervising method that keeps the stator flux linkage origin centered in the case of the DTC. In the position sensorless case, a synchronous motor can be started up with the DTC control, when a method for the determination of the initial rotor position presented in this thesis is used. The load characteristics of such a drive are not very good at low rotational speeds. Furthermore, continuous operation at a zero speed and at a low rotational speed is not possible, which is partly due to the problems related to the flux linkage estimate. For operation in a low speed area, a stator current control method based on the DFLC modulator (DMCQ is presented. With the DMCC, it is possible to start up and operate a synchronous motor at a zero speed and at low rotational speeds in general. The DMCC is necessary in situations where high torque (e.g. nominal torque) is required at the starting moment, or if the motor runs several seconds at a zero speed or at a low speed range (up to 2 Hz). The behaviour of the described methods is shown with test results. The test results are presented for the direct flux linkage and torque controlled test drive system with a 14.5 kVA, four pole salient pole synchronous motor with a damper winding and electric excitation. The static accuracy of the drive is verified by measuring the torque in a static load operation, and the dynamics of the drive is proven in load transient tests. The performance of the drive concept presented in this work is sufficient e.g. for ship propulsion and for large pump drives. Furthermore, the developed methods are almost independent of the machine parameters.

Co-produção de lipase e biossurfactante em estado sólido para utilização em biorremediação de óleos vegetais e hidrocarbonetos

Recently lipases have been increasing in prominence due to its wide industrial application. The lipase production can be influenced by different variables such as the producing microorganism, carbon sources, aeration and agitation conditions, inductor type and the geometry of the reactor. Biosurfactants are composites of surface active produced by microbial cells which reduce superficial and interfacial tensions. The objective of this study was to verify the influence of different process variables in the lipase production during a fermentative process. The results showed that the concomitant production of lipases and biosurfactant was possible in different cultivation conditions.

Energy storage in electric drive system

In recent years the environmental issues and the energy saving have become increasingly import in modern society where industry is the major emission factor and energy consumer. Generally, most of the total energy consumption is caused by electrical drives used in industrial applications and thus improving the performance of electrical drives give an opportunity to improve the energy efficiency. In this Master Thesis improving the energy efficiency in different electrical drives is clarified with different cases: regenerative braking in the electric grid or recovery of the braking energy into an energy storage. In addition, as an example, the energy consumption of an elevator is analyzed by measurements. From these measurement results it can be estimated how much the share of the standby energy consumption is from the total energy consumption and how much regenerative energy is available. The latter part of the thesis concentrates on determination of the properties of lithium iron phosphate battery with measurements.

Trauma abdominal penetrante consecutivo à corrente elétrica industrial

The authors present a case report of a victim of high power electric shock. The main electric lesion was a penetrating abdominal wound with loss of substance of the abdominal wall and an electric lesion of the hepatic segment and of the gallbladder. The surgical treatment included hepatic segmentectomy, cholecystectomy, repair of the abdominal wall with Marlex prosthesis and skin graft, besides the debridment of the lesions of extremities. The postoperative evolution was satisfactory and the follow-up for 6 months didn't show any sequelae.

Electrocoagulation in the treatment of industrial waters and wastewaters

Chemical coagulation is commonly used in raw water and wastewater treatment plants for the destabilisation of pollutants so that they can be removed in the subsequent separation processes. The most commonly used coagulation chemicals are aluminium and iron metal salts. Electrocoagulation technology has also been proposed for the treatment of raw waters and wastewaters. With this technology, metal cations are produced on the electrodes via electrolysis and these cations form various hydroxides in the water depending on the water pH. In addition to this main reaction, several side reactions, such as hydrogen bubble formation and the reduction of metals on cathodes, also take place in the cell. In this research, the applications of electrocoagulation were investigated in raw water treatment and wastewater applications. The surface water used in this research contained high concentrations of natural organic matter (NOM). The effect of the main parameters – current density, initial pH, electric charge per volume, temperature and electrolysis cell construction – on NOM removal were investigated. In the wastewater treatment studies, the removal of malodorous sulphides and toxic compounds from the wastewaters and debarking effluents were studied. Also, the main parameters of the treatment, such as initial pH and current density, were investigated. Aluminium electrodes were selected for the raw water treatment, whereas wastewaters and debarking effluent were treated with iron electrodes. According to results of this study, aluminium is more suitable electrode material for electrocoagulation applications because it produces Al(III) species. Metal ions and hydroxides produced by iron electrodes are less effective in the destabilisation of pollutants because iron electrodes produce more soluble and less charged Fe(II) species. However, Fe(II) can be effective in some special applications, such as sulphide removal. The resulting metal concentration is the main parameter affecting destabilisation of pollutants. Current density, treatment time, temperature and electrolysis cell construction affect the dissolution of electrodes and hence also the removal of pollutants. However, it seems that these parameters have minimal significance in the destabilization of the pollutants besides this effect (in the studied range of parameters). Initial pH and final pH have an effect on the dissolution of electrodes, but they also define what aluminium or iron species are formed in the solution and have an effect on the ζ-potential of all charged species in the solution. According to the results of this study, destabilisation mechanisms of pollutants by electrocoagulation and chemical coagulation are similar. Optimum DOC removal and low residual aluminium can be obtained simultaneously with electrocoagulation, which may be a significant benefit of electrocoagulation in surface water treatment compared to chemical coagulation. Surface water treatment with electrocoagulation can produce high quality water, which could be used as potable water or fresh water for industrial applications. In wastewater treatment applications, electrocoagulation can be used to precipitate malodorous sulphides to prevent their release into air. Technology seems to be able to remove some toxic pollutants from wastewater and could be used as pretreatment prior to treatment at a biological wastewater treatment plant. However, a thorough economic and ecological comparison of chemical coagulation and electrocoagulation is recommended, because these methods seem to be similar in pollutant destabilisation mechanisms, metal consumption and removal efficiency in most applications.

“Valley co-creation” – exploring the emergence of a cultural product in an entrepreneur-driven value network: Case study: Black Weekend festival

The interconnected domains are attracting interest from industries and academia, although this phenomenon, called ‘convergence’ is not new. Organizational research has indeed focused on uncovering co-creation for manufacturing and the industrial organization, with limited implications to entrepreneurship. Although convergence has been characterized as a process connecting seemingly disparate disciplines, it is argued that these studies tend to leave the creative industries unnoticed. With the art market boom and new forms of collaboration riding past the institution-focused arts marketing literature, this thesis takes a leap to uncover the processes of entrepreneurship in the emergence of a cultural product. As a symbolic work of synergism itself, the thesis combines organizational theory with literature in natural sciences and arts. Assuming nonlinearity, a framework is created for analysing aesthetic experience in an empirical event where network actors are connected to multiple contexts. As the focal case in study, the empirical analysis performed for a music festival organized in a skiing resort in the French Alps in March. The researcher attends the festival and models its cocreation process by enquiring from an artist, festival organisers, and a festival visitor. The findings contribute to fields of entrepreneurship, aesthetics and marketing mainly. It is found that the network actors engage in intimate and creative interaction where activity patterns are interrupted and cultural elements combined. This process is considered to both create and destruct value, through identity building, legitimisation, learning, and access to larger audiences, and it is considered particularly useful for domains where resources are too restrained for conventional marketing practices. This thesis uncovered the role of artists and informants and posits that particularly through experience design, this type of skilled individual be regarded more often as a research informant. Future research is encouraged to engage in convergence by experimenting with different fields and research designs, and it is suggested that future studies could arrive at different descriptive results.

Evidencing and Sharing Value with Decision Making Models in an Industrial Maintenance Network

The objective of this thesis is to concretize the potential benefits that the industrial maintenance case network could achieve through using the value-based life-cycle model and the flexible asset management model. It is also inspected what factors prevent value creation and sharing in the maintenance contract practices of the case network. This thesis is a case study which utilizes modelling. Four scenarios were developed to demonstrate value creation in the future. The data was partly provided by the collaborating company, partly gathered from public financial statement information. The results indicate that value has been created through the past maintenance of the collaborating company’s rod mill and that profitability of the collaborating company has been mostly on satisfactory level during the past few years. Potential value might be created by increasing the share of proactive maintenance of the rod mill in the future. Profitability of the network could be improved in the future through flexible asset management operations. The main obstacle for value creation and sharing seems to be the lack of sufficient trust between the network members.

Co-creating value with customers as a new approach of entering new market

Global trends associated with development of information technology, globalization, industrial and economic changes are influencing on company and customer domains and thus transforming company-customer relationship. The company centric paradigm with a strong product focus shifts to a customer oriented one with a strong emphasis on customer collaboration. As a result, the customer role changes from a passive observer to an active player. Moreover, global trends contribute to transformation of competitive environment making it tougher and simplifying an access to resources previously considered as unique. All that factors push the companies towards cooperation with customers in order to identify unarticulated needs and finding the best possible solution to existing customer problems. The Master’s Thesis is done for Outotec (Lappeenranta) which considers extension of dewatering business in Russian coal market. Research aims to identify key features of coal preparation and dewatering of fine coal and tailings in Russian preparation plants; analyze the state of Russian coal market and evaluate market potential for Outotec dewatering solutions. The study has a qualitative nature and implements an action research methodology that involves both creation of knowledge and introduction of changes into the system. The base for taking actions is formed by theoretical framework that targets on describing company - customer interaction and has selected co-creation as the most appropriate method of customer involvement. The integration of co-creation approach into an action research cycle allows not only fulfilling the research objectives but also facilitates organizational learning and intraorganizational collaboration, assists in establishing customer contacts and making the first steps into the market, bringing new joint projects to the company and opening real business opportunities.

Reporting of Green Supply Chain Management and Industrial Symbiosis

The purpose of this thesis is to examine how the reporting of operations related to green supply chain management and industrial symbiosis has evolved in UPM, Fortum and Kemira within the last ten years. The focus is on the improved operations, which are studied based on annual reports of these companies. The study provides a deeper understanding of the nature of green supply chain management and industrial symbiosis as well as the possibilites that their combination offers. The research is part of the DemaNET research project The study indicates that the environmental regulations and reporting standards have forced the studied companies to report their operations related to green supply chain management and industrial symbiosis more in detail during the last ten years. The operations related to green supply chain management in the studied companies are more common compared to operations related to industrial symbiosis. Often these two operations were also partially integrated, indicating a hybrid model. Even though firms often used hybrid models they still focused mainly on greening the internal operations rather than finding alternative ways for symbiosis outside the organization. The integration of green supply chain management and industrial symbiosis is most likely to occur when mutually beneficial relationships align the interests of all parties, thus resulting in the co-creation of value. The findings suggest that identifying mutual benefits and the flow of by-products are the ones that companies should give more attention to.

Direct-Driven Interior Magnet Permanent Magnet Synchronous Motors for a Full Electric Sports Car

The design process of direct-driven permanent magnet synchronous machines (PMSMs) for a full electric 4 ´ 4 sports car is presented. The rotor structure of the machine consists of two permanent magnet layers embedded inside the rotor laminations thus resulting in some inverse saliency, where the q-axis inductance is larger than the d-axis one. An integer slot stator winding was selected to fully take advantage of the additional reluctance torque. The performance characteristics of the designed PMSMs were calculated by applying a twodimensional finite element method. Cross-saturation between the d- and q-axes was taken into account in the calculation of the synchronous inductances. The calculation results are validated by measurements.

The feasibility of torrefaction for the co-firing of wood in pulverised-fuel boilers

Torrefaction is the partial pyrolysis of wood characterised by thermal degradation of predominantly hemicellulose under inert atmosphere. Torrefaction can be likened to coffee roasting but with wood in place of beans. This relatively new process concept makes wood more like coal. Torrefaction has attracted interest because it potentially enables higher rates of co-firing in existing pulverised-coal power plants and hence greater net CO2 emission reductions. Academic and entrepreneurial interest in torrefaction has sky rocketed in the last decade. Research output has focused on the many aspects of torrefaction – from detailed chemical changes in feedstock to globally-optimised production and supply scenarios with which to sustain EU emission-cutting directives. However, despite its seemingly simple concept, torrefaction has retained a somewhat mysterious standing. Why hasn’t torrefied pellet production become fully commercialised? The question is one of feasibility. This thesis addresses this question. Herein, the feasibility of torrefaction in co-firing applications is approached from three directions. Firstly, the natural limitations imposed by the structure of wood are assessed. Secondly, the environmental impact of production and use of torrefied fuel is evaluated and thirdly, economic feasibility is assessed based on the state of the art of pellet making. The conclusions reached in these domains are as follows. Modification of wood’s chemical structure is limited by its naturally existing constituents. Consequently, key properties of wood with regards to its potential as a co-firing fuel have a finite range. The most ideal benefits gained from wood torrefaction cannot all be realised simultaneously in a single process or product. Although torrefaction at elevated pressure may enhance some properties of torrefied wood, high-energy torrefaction yields are achieved at the expense of other key properties such as heating value, grindability, equilibrium moisture content and the ability to pelletise torrefied wood. Moreover, pelletisation of even moderately torrefied fuels is challenging and achieving a standard level of pellet durability, as required by international standards, is not trivial. Despite a reduced moisture content, brief exposure of torrefied pellets to water from rainfall or emersion results in a high level of moisture retention. Based on the above findings, torrefied pellets are an optimised product. Assessment of energy and CO2-equivalent emission balance indicates that there is no environmental barrier to production and use of torrefied pellets in co-firing. A long product transport distance, however, is necessary in order for emission benefits to exceed those of conventional pellets. Substantial CO2 emission reductions appear possible with this fuel if laboratory milling results carry over to industrial scales for direct co-firing. From demonstrated state-of-the-art pellet properties, however, the economic feasibility of torrefied pellet production falls short of conventional pellets primarily due to the larger capital investment required for production. If the capital investment for torrefied pellet production can be reduced significantly or if the pellet-making issues can be resolved, the two production processes could be economically comparable. In this scenario, however, transatlantic shipping distances and a dry fuel are likely necessary for production to be viable. Based on demonstrated pellet properties to date, environmental aspects and production economics, it is concluded that torrefied pellets do not warrant investment at this time. However, from the presented results, the course of future research in this field is clear.

Production of magnesium carbonates from serpentinites for CO2 mineral sequestration : optimisation towards industrial application

Global warming is one of the most alarming problems of this century. Initial scepticism concerning its validity is currently dwarfed by the intensification of extreme weather events whilst the gradual arising level of anthropogenic CO2 is pointed out as its main driver. Most of the greenhouse gas (GHG) emissions come from large point sources (heat and power production and industrial processes) and the continued use of fossil fuels requires quick and effective measures to meet the world’s energy demand whilst (at least) stabilizing CO2 atmospheric levels. The framework known as Carbon Capture and Storage (CCS) – or Carbon Capture Utilization and Storage (CCUS) – comprises a portfolio of technologies applicable to large‐scale GHG sources for preventing CO2 from entering the atmosphere. Amongst them, CO2 capture and mineralisation (CCM) presents the highest potential for CO2 sequestration as the predicted carbon storage capacity (as mineral carbonates) far exceeds the estimated levels of the worldwide identified fossil fuel reserves. The work presented in this thesis aims at taking a step forward to the deployment of an energy/cost effective process for simultaneous capture and storage of CO2 in the form of thermodynamically stable and environmentally friendly solid carbonates. R&D work on the process considered here began in 2007 at Åbo Akademi University in Finland. It involves the processing of magnesium silicate minerals with recyclable ammonium salts for extraction of magnesium at ambient pressure and 400‐440⁰C, followed by aqueous precipitation of magnesium in the form of hydroxide, Mg(OH)2, and finally Mg(OH)2 carbonation in a pressurised fluidized bed reactor at ~510⁰C and ~20 bar PCO2 to produce high purity MgCO3. Rock material taken from the Hitura nickel mine, Finland, and serpentinite collected from Bragança, Portugal, were tested for magnesium extraction with both ammonium sulphate and bisulphate (AS and ABS) for determination of optimal operation parameters, primarily: reaction time, reactor type and presence of moisture. Typical efficiencies range from 50 to 80% of magnesium extraction at 350‐450⁰C. In general ABS performs better than AS showing comparable efficiencies at lower temperature and reaction times. The best experimental results so far obtained include 80% magnesium extraction with ABS at 450⁰C in a laboratory scale rotary kiln and 70% Mg(OH)2 carbonation in the PFB at 500⁰C, 20 bar CO2 pressure for 15 minutes. The extraction reaction with ammonium salts is not at all selective towards magnesium. Other elements like iron, nickel, chromium, copper, etc., are also co���extracted. Their separation, recovery and valorisation are addressed as well and found to be of great importance. The assessment of the exergetic performance of the process was carried out using Aspen Plus® software and pinch analysis technology. The choice of fluxing agent and its recovery method have a decisive sway in the performance of the process: AS is recovered by crystallisation and in general the whole process requires more exergy (2.48–5.09 GJ/tCO2sequestered) than ABS (2.48–4.47 GJ/tCO2sequestered) when ABS is recovered by thermal decomposition. However, the corrosive nature of molten ABS and operational problems inherent to thermal regeneration of ABS prohibit this route. Regeneration of ABS through addition of H2SO4 to AS (followed by crystallisation) results in an overall negative exergy balance (mainly at the expense of low grade heat) but will flood the system with sulphates. Although the ÅA route is still energy intensive, its performance is comparable to conventional CO2 capture methods using alkanolamine solvents. An energy‐neutral process is dependent on the availability and quality of nearby waste heat and economic viability might be achieved with: magnesium extraction and carbonation levels ≥ 90%, the processing of CO2‐containing flue gases (eliminating the expensive capture step) and production of marketable products.

Motor Types Comparison Determining Efficiency in Pumping Systems

Pumping, fan and compressor systems consume most of the motor electricity power in both the industrial and services sectors. A variable speed drive brings relevant improvements in a fluid system leading to energy saving that further on can be translated into Mtons reduction of CO 2 emissions. Standards and regulations are being adopted for fluid handling systems to limit the less efficiency pumps out of the European market on the coming years and a greater potential in energy savings is dictated by the Energy Efficiency Index (EEI) requirements for the whole pumping system and integrated pumps. Electric motors also have an International Efficiency (IE) classification in order to introduce higher efficiency motors into the market. In this thesis, the applicability of mid-size common electric motor types to industrial pumping system took place comparing the motor efficiency characteristics with each other and by analyzing the effect of motor dimensioning on the pumping system and its impact in the energy consumption.