Effect of hydrodynamics on modelling, monitoring and control of crystallization

Crystallization is a purification method used to obtain crystalline product of a certain crystal size. It is one of the oldest industrial unit processes and commonly used in modern industry due to its good purification capability from rather impure solutions with reasonably low energy consumption. However, the process is extremely challenging to model and control because it involves inhomogeneous mixing and many simultaneous phenomena such as nucleation, crystal growth and agglomeration. All these phenomena are dependent on supersaturation, i.e. the difference between actual liquid phase concentration and solubility. Homogeneous mass and heat transfer in the crystallizer would greatly simplify modelling and control of crystallization processes, such conditions are, however, not the reality, especially in industrial scale processes. Consequently, the hydrodynamics of crystallizers, i.e. the combination of mixing, feed and product removal flows, and recycling of the suspension, needs to be thoroughly investigated. Understanding of hydrodynamics is important in crystallization, especially inlargerscale equipment where uniform flow conditions are difficult to attain. It is also important to understand different size scales of mixing; micro-, meso- and macromixing. Fast processes, like nucleation and chemical reactions, are typically highly dependent on micro- and mesomixing but macromixing, which equalizes the concentrations of all the species within the entire crystallizer, cannot be disregarded. This study investigates the influence of hydrodynamics on crystallization processes. Modelling of crystallizers with the mixed suspension mixed product removal (MSMPR) theory (ideal mixing), computational fluid dynamics (CFD), and a compartmental multiblock model is compared. The importance of proper verification of CFD and multiblock models is demonstrated. In addition, the influence of different hydrodynamic conditions on reactive crystallization process control is studied. Finally, the effect of extreme local supersaturation is studied using power ultrasound to initiate nucleation. The present work shows that mixing and chemical feeding conditions clearly affect induction time and cluster formation, nucleation, growth kinetics, and agglomeration. Consequently, the properties of crystalline end products, e.g. crystal size and crystal habit, can be influenced by management of mixing and feeding conditions. Impurities may have varying impacts on crystallization processes. As an example, manganese ions were shown to replace magnesium ions in the crystal lattice of magnesium sulphate heptahydrate, increasing the crystal growth rate significantly, whereas sodium ions showed no interaction at all. Modelling of continuous crystallization based on MSMPR theory showed that the model is feasible in a small laboratoryscale crystallizer, whereas in larger pilot- and industrial-scale crystallizers hydrodynamic effects should be taken into account. For that reason, CFD and multiblock modelling are shown to be effective tools for modelling crystallization with inhomogeneous mixing. The present work shows also that selection of the measurement point, or points in the case of multiprobe systems, is crucial when process analytical technology (PAT) is used to control larger scale crystallization. The thesis concludes by describing how control of local supersaturation by highly localized ultrasound was successfully applied to induce nucleation and to control polymorphism in reactive crystallization of L-glutamic acid.

External knowledge transfer mechanisms in service business acquisition

In knowledge-intensive economy an effective knowledge transfer is a part of the firm’s strategy to achieve a competitive advantage in the market. Knowledge transfer related to a variety of mechanisms depends on the nature of knowledge and context. The topic is, however, very little empirical studied and there is a research gap in scientific literature. This study examined and analyzed external knowledge transfer mechanisms in service business and especially in the context of acquisitions. The aim was to find out what kind of mechanisms was used when the buyer began to transfer data e.g. their own agendas and practices to the purchased units. Another major research goal was to identify the critical factors which contributed to knowledge transfer through different mechanisms. The study was conducted as a multiple-case study in a consultative service business company, in its four business units acquired by acquisition, in various parts of the country. The empirical part of the study was carried out as focus group interviews in each unit, and the data were analyzed using qualitative methods. The main findings of this study were firstly the nine different knowledge transfer mechanisms in service business acquisition: acquisition management team as an initiator, unit manager as a translator, formal training, self-directed learning, rooming-in, IT systems implementation, customer relationship management, codified database and ecommunication. The used mechanisms brought up several aspects as giving the face to changing, security of receiving right knowledge and correctly interpreted we-ness atmosphere, and orientation to use more consultative touch with customers. The study pointed out seven critical factors contributed to different mechanisms: absorption, motivation, organizational learning, social interaction, trust, interpretation and time resource. The two last mentioned were new findings compared to previous studies. Each of the mechanisms and the related critical factors contributed in different ways to the activity in different units after the acquisition. The role of knowledge management strategy was the most significant managerial contribution of the study. Phenomenon is not recognized enough although it is strongly linked in knowledge based companies. The recognition would help to develop a better understanding of the business through acquisitions, especially in situations such as where two different knowledge strategies combines in new common company.

The Structural Basis for inorganic Pyrophosphatase Catalysis and Regulation

Inorganic pyrophosphatases (PPases) are essential enzymes for every living cell. PPases provide the necessary thermodynamic pull for many biosynthetic reactions by hydrolyzing pyrophosphate. There are two types of PPases: integral membrane-bound and soluble enzymes. The latter type is divided into two non-homologous protein families, I and II. Family I PPases are present in all kingdoms of life, whereas family II PPases are only found in prokaryotes, including archae. Family I PPases, particularly that from Saccharomyces cerevisiae, are among the most extensively characterized phosphoryl transfer enzymes. In the present study, we have solved the structures of wild-type and seven active site variants of S. cerevisiae PPase bound to its natural metal cofactor, magnesium ion. These structures have facilitated derivation of the complete enzyme reaction scheme for PPase, fulfilling structures of all the reaction intermediates. The main focus in this study was on a novel subfamily of family II PPases (CBSPPase) containing a large insert formed by two CBS domains and a DRTGG domain within the catalytic domain. The CBS domain (named after cystathionine beta-synthase in which it was initially identified) usually occurs as tandem pairs with two or four copies in many proteins in all kingdoms of life. The structure formed by a pair of CBS domains is also known as a Bateman domain. CBS domains function as regulatory units, with adenylate ligands as the main effectors. The DRTGG domain (designated based on its most conserved residues) occurs less frequently and only in prokaryotes. Often, the domain co-exists with CBS domains, but its function remains unknown. The key objective of the current study was to explore the structural rearrangements in the CBS domains induced by regulatory adenylate ligands and their functional consequences. Two CBS-PPases were investigated, one from Clostridium perfringens (cpCBS-PPase) containing both CBS and DRTGG domains in its regulatory region and the other from Moorella thermoacetica (mt CBS-PPase) lacking the DRTGG domain. We additionally constructed a separate regulatory region of cpCBS-PPase (cpCBS). Both full-length enzymes and cpCBS formed homodimers. Two structures of the regulatory region of cpCBS-PPase complexed with the inhibitor, AMP, and activator, diadenosine tetraphosphate, were solved. The structures were significantly different, providing information on the structural pathway from bound adenylates to the interface between the regulatory and catalytic parts. To our knowledge, these are the first reported structures of a regulated CBS enzyme, which reveal large conformational changes upon regulator binding. The activator-bound structure was more open, consistent with the different thermostabilities of the activator- and inhibitor-bound forms of cpCBS-PPase. The results of the functional studies on wild-type and variant CBS-PPases provide support for inferences made on the basis of structural analyses. Moreover, these findings indicate that CBS-PPase activity is highly sensitive to adenine nucleotide distribution between AMP, ADP and ATP, and hence to the energy level of the cell. CBS-PPase activity is markedly inhibited at low energy levels, allowing PPi energy to be used for cell survival instead of being converted into heat.

A study on rate correlations of gasification reactions

Gasification offers an environmentally friendly alternative for conventional combustion enabling the use of low grade and troublesome fuel such as municipal waste. While combustion converts fuel directly into thermal energy and noxious gases, gasification thermally converts fuel into gas that can be used in multiple applications. The purpose of this work is to get to know the gasification as a phenomenon and examine the kinetics of gasification. The main interest is in the reaction rates of the most important gasification reactions - water-gas, Boudouard and shift reaction. Reaction rate correlations found in the scientific articles are examined in atmospheric pressure in different temperatures.

Motivational Influences on Transfer: Dimensions and Boundary Conditions

The focus of this dissertation is the motivational influences on transfer in higher education and professional training contexts. To estimate these motivational influences, the dissertation includes seven individual studies that are structured in two parts. Part I, Dimensions, aims at identifying the dimensionality of motivation to transfer and its structural relations with training-related antecedents and outcomes. Part II, Boundary Conditions, aims at testing the predictive validity of motivation theories used in contemporary training research under different study conditions. Data in this dissertation was gathered from multi-item questionnaires, which were analyzed differently in Part I and Part II. Studies in Part I employed exploratory and confirmatory factor analysis, structural equation modeling, partial least squares (PLS) path modeling, and mediation analysis. Studies in Part II used artifact distribution meta-analysis, (nested) subgroup analysis, and weighted least squares (WLS) multiple regression. Results demonstrate that motivation to transfer can be conceptualized as a three-dimensional construct, including autonomous motivation to transfer, controlled motivation to transfer, and intention to transfer, given a theoretical framework informed by expectancy theory, self-determination theory, and the theory of planned behavior. Results also demonstrate that a range of boundary conditions moderates motivational influences on transfer. To test the predictive validity of expectancy theory, social cognitive theory, and the theory of goal orientations under different study settings, a total of 17 boundary conditions were meta-analyzed, including age; assessment criterion; assessment source; attendance policy; collaboration among trainees; computer support; instruction; instrument used to measure motivation; level of education; publication type; social training context; SS/SMC bias; study setting; survey modality; type of knowledge being trained; use of a control group; and work context. Together, the findings cumulated in this thesis support the basic premise that motivation is centrally important for transfer, but that motivational influences need to be understood from a more differentiated perspective than commonly found in the literature, in order to account for several dimensions and boundary conditions. The results of this dissertation across the seven individual studies are reflected in terms of their implications for theory development and their significance for training evaluation and the design of training environments. Limitations and directions to take in future research are discussed.

Frequency-Domain and Wide-Pulse Time-Domain Measurements of Lanthanide Luminescence and Lanthanide-Based Resonance Energy Transfer

Resonance energy transfer (RET) is a non-radiative transfer of the excitation energy from the initially excited luminescent donor to an acceptor. The requirements for the resonance energy transfer are: i) the spectral overlap between the donor emission spectrum and the acceptor absorption spectrum, ii) the close proximity of the donor and the acceptor, and iii) the suitable relative orientations of the donor emission and the acceptor absorption transition dipoles. As a result of the RET process the donor luminescence intensity and the donor lifetime are decreased. If the acceptor is luminescent, a sensitized acceptor emission appears. The rate of RET depends strongly on the donor–acceptor distance (r) and is inversely proportional to r6. The distance dependence of RET is utilized in binding assays. The proximity requirement and the selective detection of the RET-modified emission signal allow homogeneous separation free assays. The term lanthanide-based RET is used when luminescent lanthanide compounds are used as donors. The long luminescence lifetimes, the large Stokes’ shifts and the intense, sharply-spiked emission spectra of the lanthanide donors offer advantages over the conventional organic donor molecules. Both the organic lanthanide chelates and the inorganic up-converting phosphor (UCP) particles have been used as donor labels in the RET based binding assays. In the present work lanthanide luminescence and lanthanide-based resonance energy transfer phenomena were studied. Luminescence lifetime measurements had an essential role in the research. Modular frequency-domain and time-domain luminometers were assembled and used successfully in the lifetime measurements. The frequency-domain luminometer operated in the low frequency domain ( 100 kHz) and utilized a novel dual-phase lock-in detection of the luminescence. One of the studied phenomena was the recently discovered non-overlapping fluorescence resonance energy transfer (nFRET). The studied properties were the distance and temperature dependences of nFRET. The distance dependence was found to deviate from the Förster theory and a clear temperature dependence was observed whereas conventional RET was completely independent of the temperature. Based on the experimental results two thermally activated mechanisms were proposed for the nFRET process. The work with the UCP particles involved the measurement of the luminescence properties of the UCP particles synthesized in our laboratory. The goal of the UCP particle research is to develop UCP donor labels for binding assays. In the present work the effect of the dopant concentrations and the core–shell structure on the total up-conversion luminescence intensity, the red–green emission ratio, and the luminescence lifetime was studied. Also the non-radiative nature of the energy transfer from the UCP particle donors to organic acceptors was demonstrated for the first time in aqueous environment and with a controlled donor–acceptor distance.

Cyanobacteria from the Baltic Sea and Finnish lakes as an energy source and modulators of bioenergetic pathways

Cyanobacteria are a diverse group of oxygenic photosynthetic bacteria that inhabit in a wide range of environments. They are versatile and multifaceted organisms with great possibilities for different biotechnological applications. For example, cyanobacteria produce molecular hydrogen (H2), which is one of the most important alternatives for clean and sustainable energy. Apart from being beneficial, cyanobacteria also possess harmful characteristics and may become a source of threat to human health and other living organisms, as they are able to form surface blooms that are producing a variety of toxic or bioactive compounds. The University of Helsinki Culture Collection (UHCC) maintains around 1,000 cyanobacterial strains representing a large number of genera and species isolated from the Baltic Sea and Finnish lakes. The culture collection covers different life forms such as unicellular and filamentous, N2-fixing and non-N2-fixing strains, and planktonic and benthic cyanobacteria. In this thesis, the UHCC has been screened to identify potential strains for sustainable biohydrogen production and also for strains that produce compounds modifying the bioenergetic pathways of other cyanobacteria or terrestrial plants. Among the 400 cyanobacterial strains screened so far, ten were identified as high H2-producing strains. The enzyme systems involved in H2 metabolism of cyanobacteria were analyzed using the Southern hybridization approach. This revealed the presence of the enzyme nitrogenase in all strains tested, while none of them are likely to have contained alternative nitrogenases. All the strains tested, except for two Calothrix strains, XSPORK 36C and XSPORK 11A, were suggested to contain both uptake and bidirectional hydrogenases. Moreover, 55 methanol extracts of various cyanobacterial strains were screened to identify potent bioactive compounds affecting the photosynthetic apparatus of the model cyanobacterium, Synechocystis PCC 6803. The extract from Nostoc XPORK 14A was the only one that modified the photosynthetic machinery and dark respiration. The compound responsible for this effect was identified, purified, and named M22. M22 demonstrated a dual-action mechanism: production of reactive oxygen species (ROS) under illumination and an unknown mechanism that also prevailed in the dark. During summer, the Baltic Sea is occupied by toxic blooms of Nodularia spumigena (hereafter referred to as N. spumigena), which produces a hepatotoxin called nodularin. Long-term exposure of the terrestrial plant spinach to nodularin was studied. Such treatment resulted in inhibition of growth and chlorosis of the leaves. Moreover, the activity and amount of mitochondrial electron transfer complexes increased in the leaves exposed to nodularin-containing extract, indicating upregulation of respiratory reactions, whereas no marked changes were detected in the structure or function of the photosynthetic machinery. Nodularin-exposed plants suffered from oxidative stress, evidenced by oxidative modifications of various proteins. Plants initiated strategies to combat the stress by increasing the levels of alpha-tocopherol, mitochondrial alternative oxidase (AOX), and mitochondrial ascorbate peroxidase (mAPX).

Effective diffusivity and convective mass transfer coefficient during the drying of bananas

In this article, a methodology is used for the simultaneous determination of the effective diffusivity and the convective mass transfer coefficient in porous solids, which can be considered as an infinite cylinder during drying. Two models are used for optimization and drying simulation: model 1 (constant volume and diffusivity, with equilibrium boundary condition), and model 2 (constant volume and diffusivity with convective boundary condition). Optimization algorithms based on the inverse method were coupled to the analytical solutions, and these solutions can be adjusted to experimental data of the drying kinetics. An application of optimization methodology was made to describe the drying kinetics of whole bananas, using experimental data available in the literature. The statistical indicators enable to affirm that the solution of diffusion equation with convective boundary condition generates results superior than those with the equilibrium boundary condition.

Water transfer from São Francisco river to semiarid northeast of Brazil: technical data, environmental impacts, survey of opinion about the amount to be transferred

The transposition of the São Francisco River is considered one of the greatest engineering works in Brazil of all time since it will cross an extensive agricultural region of continental dimensions, involving environmental impacts, water, soil, irrigation, water payment and other multidisciplinary themes. Taking into account its importance, this subject was incorporated into a discipline of UFSCar (Federal University of São Carlos - Brazil) named "Pollution and Environmental Impacts". It was noted strong reaction against the project, even before the presentation. To allow a critical analysis, the first objective was to compile the main technical data and environmental impacts. The second objective was to detect the three most important aspects that cause reaction, concluding for the following reasons: assumption that the volume of water to be transferred was much greater than it actually is proposed in the project; lack of knowledge about similar project already done in Brazil; the idea that the artificial canal to be built was much broader than that proposed by the project. The participants' opinion about "volume to be transferred" was raised quantitatively four times: 2-undergraduate students; 1-graduate; 1-outside community. The average resulted 14 times larger than that proposed in the project, significant according to t-test. It was concluded that the reaction to water transfer project is due in part to the ignorance combined with a preconceived idea that tend to overestimate the magnitude of environmental impacts.

Intra-organizational knowledge transfer in a Finnish multinational company

The ability of a multinational company to effectively transfer knowledge from one unit to another can create a great source of competitive advantage and is crucial for long-term success. However, in their attempts to disseminate existent knowledge across national boundaries, organizations encounter several obstacles. Especially challenging is the transfer of tacit knowledge, the most valuable kind, as it is embedded in the minds and the behavior of people. The purpose of this study is to identify the main factors and challenges to be considered in intra-organizational knowledge transfer and consequently develop a framework that could be utilized to improve the process. The research is of qualitative nature and it adopts an exploratory approach. The study was further conducted as an intensive single-case study through studying a Finnish multinational company, and the researcher adopted a role as a participant observant in the research setting. Other data collection methods include semi-structured interviews and an online survey. The research findings show that knowledge transfer is currently challenging within the international sales organization of the case company. The majority of knowledge is currently concentrated in the company headquarters, and it is not always systematically distributed to the regional offices abroad. The main factor affecting knowledge transfer seems to be the organizational culture, which does not support or encourage knowledge sharing. The company is struggling in having a common place for information and employees that lack proper social networks have difficulties accessing relevant knowledge. Some recommended improvement suggestions include the institutionalization of knowledge transfer by turning it into an articulated organizational goal, and the implementation of a reward system that includes soft factors, such as teamwork and knowledge sharing behavior. Furthermore, the organizational culture should be more open and supportive in order to reinforce trust. Individuals in regional offices should be given better support by offering them dedicated mentors and increasing the amount of expatriation. Finally, knowledge should actively be codified and stored in commonly shared platforms where it is easily accessible by all employees.

Transfer of Administrative HR Services to Global Service Center in Poland

Liiketoimintaa tukevien palvelujen etätuotanto edustaa uutta kansainvälistymisen muotoa. Kehittyvien markkinoiden nousu yhdistettynä yritysten arvoketjutoimintojen kansainvälistymiseen on luonut yrityksille kasvavan paineen etsiä parasta sijaintia toiminnoilleen. Monikansalliset yritykset ovat yhä useammin korvanneet paikallisia henkilöstöpalvelujaan siirtymällä globaaliin malliin jaettujen palvelujen tuotannossa. Tämä diplomityö on toteutettu tukeakseen UPM:n henkilöstöhallintoa globaalin palvelukeskuksen perustamisessa Puolaan. Tutkimuksen tavoitteena on laajentaa käsitystä henkilöstöpalvelujen tarjontamallin uudistamiseen johtaneista tekijöistä ja motiiveista. Empiirisen tutkimuksen tärkein tavoite on tukea rekrytoinnin hallinnollisten töiden siirtoa globaaliin palvelukeskukseen palvelun laadun säilyessä vähintään aikaisemmalla tasolla. Tutkimuksen tulokset painottavat strategista näkökulmaa muutokseen. Strategiset syyt UPM:n henkilöstöhallinnon globaalin palvelukeskuksen perustamiselle sisältävät ylikapasiteetin ja päällekkäisten toimintojen vähentämisen eri maissa. Muutos lisää palvelun joustavuutta sekä edesauttaa toiminnan läpinäkyvyyttä, ennustettavuutta ja kustannusten valvontaa. Onnistuneesti toteutetut jaetut palvelut voivat toimia hyvänä lähtökohtana tehokkaiden henkilöstöpalvelujen tuottamiselle.

Fundamentals of heat transfer

Following over 170+ pages and additional appendixes are formed based on content of Course: Fundamentals of Heat Transfer. Mainly this summarizes relevant parts on Book of Fundamentals of Heat and Mass Transfer (Incropera), but also other references introducing the same concepts are included. Student’s point of view has been consideredwith following highlights: (1) Relevant topics are presented in a nutshell to provide fast digestion of principles of heat transfer. (2) Appendixes include terminology dictionary. (3) Totally 22 illustrating examples are connecting theory to practical applications and quantifying heat transfer to understandable forms as: temperatures, heat transfer rates, heat fluxes, resistances and etc. (4) Most important Learning outcomes are presented for each topic separately. The Book, Fundamentals of Heat and Mass Transfer (Incropera), is certainly recommended for those going beyond basic knowledge of heat transfer. Lecture Notes consists of four primary content-wise objectives: (1) Give understanding to physical mechanisms of heat transfer, (2)Present basic concepts and terminology relevant for conduction, convection and radiation (3) Introduce thermal performance analysis methods for steady state and transient conduction systems. (4) Provide fast-to-digest phenomenological understanding required for basic design of thermal models

Cross-cultural knowledge transfer within a multinational company

The ability to share knowledge efficiently is vital in day-to-day operations of multinational companies. Therefore, the tools for the effective knowledge sharing along with the transfer knowledge models are of a primary interest for the companies. Knowledge transfer often involves participants of different cultural background. The purpose of this research is to investigate how the cross-cultural knowledge transfer in a multinational corporation takes place and how the successful knowledge transfer is ensured. The four sub-questions will help to answer the research question. Firstly, the author will try to identify what difficulties might occur while transferring knowledge in a multicultural environment. Secondly, the cultural differences’ impact on cross-cultural communication will be explored. Thirdly, the tools and models for effective tacit knowledge transfer will be covered by the author. Lastly, the methods of assessing if a knowledge transfer was successful or not will be discussed. The focus of this thesis is on knowledge transfer within a multinational setting. A multinational corporation is used as a practical example for this study; namely the Training Centre of the multinational corporation. The study was carried out by using a qualitative research approach. The four employees of the Training Centre were interviewed in order to obtain the answers to the research questions. The complete idea of the data gathering process can be obtained by reading through the first part of the methodology section Furthermore, the matters of transferability, confirmability, trustworthiness and objectivity were discussed in the methodological section. The study indicates that in order to carry out the successful and efficient knowledge transfer several requests have to be met. Mutual motivation, e.g. the motivation of both knowledge sender and knowledge receiver is one of the most important determinants of knowledge transfer. Sufficient and bearable workload for the knowledge senders is important to ensure the quality and involvement of the knowledge sender into knowledge transfer process. Course contents, infrastructure and other matters will be discussed further on in relation of successful knowledge transfer. Influences of cultural differences on knowledge sharing were studied in this thesis. At the end of the empirical study- a model used to transfer knowledge in Training Centre will be presented. The model created proves to be functional and appropriate for transferring knowledge to representatives of different cultures.

Education export as a form of knowledge transfer : The potential of Finnish education export in Chile

Knowledge transfer is a complex process. Knowledge transfer in the form of exporting education products from one system of education to another is particularly complicated, because each system has been developed in a particular context to meet the requirements seen as relevant at each time. National innovation systems are often seen to form an essential framework within which the development of a country, its economy and level of knowledge are considered and promoted. These systems are orientated towards the future, and as such they also provide a framework for the knowledge transfer related to the development of education. In the best of circumstances they are able to facilitate and boost this transfer both from the viewpoint of the provider and the recipient. The leading thought and the idea of the study is that education export is a form of knowledge transfer, which is illustrated by the existing models included. The purpose of this study is to explore, analyze and describe the factors and phenomena related to education export, and more specifically, those related to the experiences and potential of Finnish education export to Chile. For better understanding, of the multiplicity of the issue involved, the current status of education export between Finland and Chile and he existing efforts within the Finnish innovation network will be outlined as well as new forms of co-operation between Finland and Chile in educational matters explored. Several countries have started to commercialize their education system in order to establish themselves as emerging education exporters. Moreover, the demand for education reform is accurate in many developing countries. This offers a good match between Finland and Chile to be the example countries of the research. The main research findings suggest that there are several business areas in education export. These include degrees in education, training services and education technologies for example The factors that influence education export can be divided into four groups, including academic, cultural, political and economic aspects. Challenges to overcome include the lack of product or services to be sold, lack of market and cultural knowledge of the buyer country, financing and lack of suitable pricing model. National innovation systems could be seen as enabling entities for successful education export. The extensive networks that national innovation systems aim to form, could operate as a basis for joining the forces in selling knowledge as well as receiving knowledge in a constructive way.