998 resultados para heat value
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Microbial lipase from Candida rugosa was immobilized by covalent binding on wood cellulignin (Eucaliptus grandis) chemically modified with carbonyldiimidazole. The immobilized system was fully evaluated in aqueous (olive oil hydrolysis) and organic (ester synthesis) media. A comparative study between free and immobilized lipase was carried out in terms of pH, temperature and thermal stability. A higher pH value (8.0) was found optimal for the immobilized lipase. The optimal reaction temperature shifted from 37 °C for the free lipase to 45 °C for the immobilized lipase. The pattern of heat stability indicated that the immobilization process tends to stabilize the enzyme. Kinetics tests at 37 °C following the hydrolysis of olive oil obeyed the Michaelis-Menten rate equation. Values for Km = 924.9 mM and Vmax = 198.3 U/mg were lower than for free lipase, suggesting that the affinity towards the substrate changed and the activity of the immobilized lipase decreased during the course of immobilization. The immobilized derivative was also tested in the ester synthesis from several alcohols and carboxylic acids.
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The identifiability of the parameters of a heat exchanger model without phase change was studied in this Master’s thesis using synthetically made data. A fast, two-step Markov chain Monte Carlo method (MCMC) was tested with a couple of case studies and a heat exchanger model. The two-step MCMC-method worked well and decreased the computation time compared to the traditional MCMC-method. The effect of measurement accuracy of certain control variables to the identifiability of parameters was also studied. The accuracy used did not seem to have a remarkable effect to the identifiability of parameters. The use of the posterior distribution of parameters in different heat exchanger geometries was studied. It would be computationally most efficient to use the same posterior distribution among different geometries in the optimisation of heat exchanger networks. According to the results, this was possible in the case when the frontal surface areas were the same among different geometries. In the other cases the same posterior distribution can be used for optimisation too, but that will give a wider predictive distribution as a result. For condensing surface heat exchangers the numerical stability of the simulation model was studied. As a result, a stable algorithm was developed.
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Some bilingual societies exhibit a distribution of language skills that can- not be explained by economic theories that portray languages as pure commu- nication devices. Such distribution of skills are typically the result of public policies that promote bilingualism among members of both speech commu- nities (reciprocal bilingualism). In this paper I argue that these policies are likely to increase social welfare by diminishing economic and social segmenta- tion between the two communities. However, these gains tend to be unequally distributed over the two communities. As a result, in a large range of circum- stances these policies might not draw su¢ cient support. The model is built upon the communicative value of languages, but also emphasizes the role of linguistic preferences in the behavior of bilingual individuals.
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Tutkielmassa selvitetään monimutkaisen indeksiobligaation arvon määritystä obligaation juoksuaikana. Tutkittava indeksiobligaatio sijoittaa osakkeisiin, korkoon ja raaka aineisiin. Kyseisessä indeksi-obligaatiossa sijoitetaan korioptioihin ja ne ovat lisäksi niiltä osin kvantto optioita, kun positio on ollut tarpeen suojata valuutta kurssimuutoksia vastaan. Tämän lisäksi indeksiobligaatio sijoittaa nolla kuponkilainaan. Sijoittajalle on haastavaa ymmärtää oikein ja läpinäkyvästi monimutkaisen osakeindeksiobligaation arvonmääritystä sen juoksuaikana. Tässä tutkielmassa avataan monimutkaisen osakeindeksiobligaation arvonmäärityksen perusteet. Tutkielmassa huomataan, että sijoittajalla voi helposti olla vaara mielikuva siitä, miten arvo määrittyy. Tämä johtuu siitä, että arvonmääritys eroaa huomattavasti siitä mikä käy ilmi velkakirjan ehdoissa. Tutkielman keskeisin anti on se, että kyseinen osakeindeksiobligaatio antaa heikkoa tuottoa kesken juoksuajan, mikäli joko osakkeet, raaka-aineet tai korot kehittyvät negatiivisesti. Lisaksi raaka aineoptioiden hinnan määritys eroaa siitä, mitä sijoittaja olettaa sen olevan velkakirjan ehtoja lukiessaan. Raaka-aineiden hinnat määritellään forward hinnoista
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The traditional forest industry is a good example of the changing nature of the competitive environment in many industries. Faced with drastic challenges forestindustry companies are forced to search for new value-creating strategies in order to create competitive advantage. The emerging bioenergy business is now offering promising avenues for value creation for both the forest and energy sectors because of their complementary resources and knowledge with respect to bioenergy production from forest-based biomass. The key objective of this dissertation is to examine the sources of sustainable competitive advantage and the value-creation opportunities that are emerging at the intersection between the forest and energy industries. The research topic is considered from different perspectives in order to provide a comprehensive view of the phenomenon. The study discusses the business opportunities that are related to producing bioenergy from forest-based biomass, and sheds light on the greatest challenges and threats influencing the success of collaboration between the forest and energy sectors. In addition, it identifies existing and potential bioenergy actors, and considers the resources and capabilities needed in order to prosper in the bioenergy field. The value-creation perspective is founded on strategic management accounting, the theoretical frameworks are adopted from the field of strategic management, and the future aspect is taken into account through the application of futures studies research methodology. This thesis consists of two parts. The first part provides a synthesis of the overall dissertation, and the second part comprises four complementary research papers. There search setting is explorative in nature, and both qualitative and quantitative research methods are used. As a result, the thesis lays the foundation for non-technological studies on bioenergy. It gives an example of how to study new value-creation opportunities at an industrial intersection, and discusses the main determinants affecting the value-creation process. In order to accomplish these objectives the phenomenon of value creation at the intersection between the forest and energy industries is theorized and connected with the dynamic resource-based view of the firm.
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The moisture sorption isotherms of Chilean papaya were determined at 5, 20, and 45 ºC, over a relative humidity range of 10-95%. The GAB, BET, Oswin, Halsey, Henderson, Smith, Caurie and Iglesias-Chirife models were applied to the sorption experimental data. The goodness of fit of the mathematical models was statistically evaluated by means of the determination coefficient, mean relative percentage deviation, sum square error, root-mean-square error, and chi-square values. The GAB, Oswin and Halsey models were found to be the most suitable for the description of the sorption data. The sorption heats calculated using the Clausius-Clapeyron equation were 57.35 and 59.98 kJ·mol-1, for adsorption and desorption isotherms, respectively.
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Tämä diplomityö on tehty IMMU-hankkeeseen, jossa selvitetään konkreettisia keinoja ilmastonmuutoksen hillintään Lahden seudulla. Diplomityössä tarkastellaan mahdollisuuksia lisätä biopolttoaineita pienen kokoluokan kaukolämmön tuotantolaitoksissa. Teoria osuuden pohjalta luodaan skenaariot Nastolaan ja Vääksyyn (Asikkala). Skenaarioissa tarkastellaan biopolttoaineiden lisäämisen vaikutuksia kasvihuonekaasu- ja hiukkaspäästöihin käyttämällä elinkaariarviointimenetelmää. Taloudellisia seikkoja tarkastellaan laskemalla takaisinmaksuaikoja eri biolaitosratkaisuille nettonykyarvomenetelmällä. Tutkimuksen tuloksena saatiin, että kasvihuonekaasupäästöt tuotannon elinkaaren ajalta vähenevät eniten tuottamalla kaukolämmön perustuotanto Nastolassa ja Vääksyssä bio-CHP-laitoksella haketta polttamalla. Kiinteitä biopolttoaineita poltettaessa tulevat kuitenkin suurimmat hiukkaspäästöt, mikä vaikuttaa asuinympäristön viihtyvyyteen tuotantolaitoksen läheisyydessä. Bio-CHP-laitoksen investointikustannukset ovat suurimmat ja takaisinmaksuaika pisin. Nastolan kulutusperusteisiä päästöjä pystytään vähentämään eniten investoimalla biolämpölaitokseen tai bio-CHP-laitokseen. Päästöjä Nastolassa pystyttäisiin kyseisillä investoinneilla vähentämään enimmillään 6,4 %. Lahti energian kokonaispäästöjä pystyttäisiin enimmillään vähentämään noin 1,6 %. Johtopäätöksenä tutkimuksesta voidaan sanoa, että kasvihuonekaasupäästöjä pystytään vähentämään investointien avulla. Toiset ratkaisut ovat vain kalliimpia kuin toiset. Lisäksi kiinteitä biopolttoaineita käytettäessä jotkut poltto-ominaisuudet voivat heiketä esim. verrattuna maakaasun polttoon. Biopolttoaineiden lisäämisellä kuitenkin päästään irti riippuvuudesta fossiilisiin polttoaineisiin kuten öljyyn ja maakaasuun. Investointeja tehdessä on vaikea sanoa suoraan, mikä vaihtoehto on paras tapa tuottaa kaukolämpöä. Investointipäätöksiä tehdessä päätökseen vaikuttaa se, mitä tuotannon ominaispiirteitä painotetaan eniten.
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Collaboration between competing firms (coopetition) has emerged as an important issue forn business practice in many industries. Extant literature has examined coopetition on many levels of analysis, but lacks clarity in distinguishing it explicitly from cooperation between noncompeting organizations. Because of this, the performance implications of coopetition from the perspective of an individual firm are still ambiguous – some research suggests positive results whereas other studies suggest detrimental outcomes. The aim in this dissertation is to narrow these gaps by exploring how firms create and appropriate value through collaboration with their competitors. The dissertation is divided into two parts. The first part comprises an overview of the relevant literature, as well as the conclusions of the whole study, and the second part includes six research publications. Both qualitative and quantitative methodologies are utilized. The results suggest that coopetition embodies the distinctive logic of value creation and appropriation from the perspective of an individual firm, and thus differs in terms of performance implications from cooperation between non-competitors. The distinction comes from the fact that competitors have somewhat similar understanding, capabilities and interest related to certain markets, which is potentially both challenging and beneficial in terms of the individual firm’s competitiveness. It appears from the findings that there are distinctive firm-external and firm-specific factors affecting the success of a coopetition strategy. This study makes three main contributions. First, on the conceptual level it shows the distinction between coopetition and cooperation between non-rivals as a collaborative inter-organizational relationship. Secondly, it sets out a framework and propositions that enhance understanding of how value is created and appropriated in coopetition from the perspective of an individual firm. Thirdly, it offers empirical evidence of how coopetition affects firms’ innovation and market performance, and identifies the focal internal and external factors involved. In general terms, the thesis adds to our knowledge of how a firm can successfully utilize a coopetition strategy in its pursuit of improved performance.
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Customer specific functionalities are a challenging part of procurement and invoice automation environments. In Basware Enterprise Purchase to Payment product family the customer specific reports are supported only in a basic level without any seamless interface between all EPP products. Also other customer specific functionalities are not supported as there is no customizable interface between the applications and only the most common features are implemented to the products themselves. In this thesis foundations are created for a new web based value added module where it is possible to create seamless customer specific functionalities throughout the whole EPP product family. The work is implemented in a Proof of Concept type of piloting. The system is created in user centered way where the users are able to explain their requests and determine their needs. The result is an excellent foundation for a module that can be developed further.
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The aim of this master’s thesis is to develop an algorithm to calculate the cable network for heat and power station CHGRES. This algorithm includes important aspect which has an influence on the cable network reliability. Moreover, according to developed algorithm, the optimal solution for modernization cable system from economical and technical point of view was obtained. The conditions of existing cable lines show that replacement is necessary. Otherwise, the fault situation would happen. In this case company would loss not only money but also its prestige. As a solution, XLPE single core cables are more profitable than other types of cable considered in this work. Moreover, it is presented the dependence of value of short circuit current on number of 10/110 kV transformers connected in parallel between main grid and considered 10 kV busbar and how it affects on final decision. Furthermore, the losses of company in power (capacity) market due to fault situation are presented. These losses are commensurable with investment to replace existing cable system.
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Supplier relationships are key elements of supply management and thus have attracted substantial research interest among academics and practitioners. The collaborative nature of relationships has been the focus of the mainstream research, and limited interest has been channelled towards power in buyer–supplier relationships. However, power is one of the key factors determining the outcomes in many business relations. Hence, one of the main objectives of this dissertation is to clarify how power may influence the nature of buyer–supplier relationships and, moreover, the depth of collaboration. Another main objective is to clarify the role of power relations in strategic supply management. Given the different nature of relationships, the firm needs divergent strategies in its supply management in order to handle them efficiently. Power has been identified as one of the factors that affect the nature of buyer–supplier relationships, and firms should thus develop strategies for handling power relations. Three research questions are addressed in pursuit of these objectives, the aim being to clarify the sources of power, the influence of power on collaboration, and the role of buyer–supplier relationships in the firm’s supply strategy. This dissertation has two parts. The first part provides a synthesis of the overall dissertation, and the second part comprises five complementary research papers. The qualitative research method is applied in an empirical case study from the Finnish food industry. The main contribution of this dissertation is that it clarifies the role of power relations in strategic supply management in value nets, and discloses the nature of power as an influencing factor in supplier relationships. It extends the discussion on power in buyer– supplier relationships in highlighting the context of networks and raising the question of network effects on power relations. It also illustrates how power positions and power relations in value nets can be determined based on the sources of power of the network actors, and shows their influence on collaboration.
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The research of virtual professional networks has been enormous but the lack of research in the dental field was obvious. This study focuses on those uses and gratifications, and motives of participants that a virtual pro-fessional network should fulfil. The aim of this study is to understand the factors behind the successful virtual professional network, and motives of participants that support a particular business network’s building up for contributing its further success. In this study the focus is on particular mo-tives, needs and benefits of participants that are significant for the net-work’s further development. The study will explore relevant scientific research and theory that is char-acteristic in networking, and theories of user’s needs and motives. Empiri-cal data was collected from dental professionals by net based question-naire that was sent by e-mail. Data analysis was done by quantitative fac-tor analysis. The findings of this study were obvious that virtual knowledge of implantology is inadequate and knowledge is rather difficult to find in the Internet. Sharing of virtual knowledge, net-learning and communication were seen to improve the quality of impolantological professionalism and also the development of these areas was experienced essential. On the grounds of this study a host of a virtual professional network can focus on those aspects that serve the users at best, can develop professionalism in implantology and can profit in its own business operations.