1000 resultados para Tuominen, Heikki


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Erilaiset sterilointitarpeet ovat olennainen osa biotekniikkaa. Steriloinnit ovat huomattava kuluerä energia-, materiaali- ja laitekäyttöjen takia ja puutteellinen sterilointi voi aiheuttaa huomattavia ylimääräisiä kustannuksia. Eniten teollisesti käytettäviä sterilointimenetelmiä ovat steriilisuodatus, lämpösterilointi, kemiallinen sterilointi ja säteilysterilointi. Näistä lämpösterilointi on selvästi käytetyin menetelmä. Kirjallisuusosassa käsitellään lämpösteriloinnin kinetiikka ja sterilointityön laskentaan käytetyt menetelmät. Lämpösteriloinnin kinetiikka on mikrobista ja sen olomuodosta riippuvainen ja noudattaa Arrheniuksen lakia. Kirjallisuusosassa käsitellään myös lämpösterilointiin käytettyjä laitteistoja. Soveltavassa osassa käsitellään panos- ja jatkuvatoimia lämpösterilointeja. Työssä käydään läpi glukoosisiirapin sterilointi vastaavan kapasiteetin panos- ja jatkuvatoimisella sterilointilaitteistolla ja vertaillaan tarvittavia energia- ja hyödykemääriä. Soveltavan osan tietojen perusteella tehdään vertailu eri lämpösterilointimenetelmien kustannuksista sekä muista hyvistä ja huonoista puolista.

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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.

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Tutkimuksen tarkoituksena on pyrkiä selvittämään kansainvälisen tilipäätösstandardin, IFRS 2 Osakeperusteiset maksut, vaikutusta yritysten palkitsemisjärjestelmäkäytäntöihin standardin voimaanastumisesta aina nykyhetkeen saakka. Tarkastelun ensisijaisena pyrkimyksenä on selvittää, miten osakeperusteiset palkitsemisjärjestelmät, kirjataan yritysten tilinpäätöksiin. Tutkimuksessa on myös tarkoitus yritysten tilinpäätösinformaatioiden kautta pyrkiä tuomaan esille osakeperusteisten maksujen tilinpäätöksellinen vaikutus, eli selvittää, millaisia vaikutuksia osakeperusteisten maksujen kirjaamisella on yritysten tunnusluvuille.

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Kirjallisuustyönä toteutettu kandidaatintyö käsittelee riskienhallinnan strategioita ja menetelmiä keskittyen erityisesti pienten ja keskisuurten yritysten näkökulmaan. Termien ja määritelmien jälkeen esitellään laskennallisia tapoja arvioida riskejä ja esitellään tärkeimmät pk-yrityksen kohtaamat riskilajit. Riskilajien pääluokat ovat strategiset riskit, operatiiviset riskit, taloudelliset riskit ja vahinkoriskit. Strategista riskienhallintaa käsittelevä osuus määrittelee riskienhallinnan tyypilliset tavoitteet ja roolin, riskienhallinnan perusstrategiat, ja esittelee Enterprise Risk Management (ERM) –konseptin ja ehdotuksen riskienhallintaprosessin viitekehykseksi, jota voidaan käyttää systematisoimaan riskienhallintatoimintaa yrityksessä. Lisäksi käsitellään lyhyesti strategiatyön ja riskienhallinnan yhteyttä ja yrityksen elinkaaren eri vaiheissa riskienhallinnan näkökulmasta huomioon otettavia asioita. Lopussa esitellään riskientunnistamisen ja -arvioinnin menetelmiä ja käytännön toimenpiteitä, joilla riskejä voidaan poistaa, pienentää, tai siirtää.

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The objective of this thesis is to research Manufacturing Planning and Control (MPC) system and Master Scheduling (MS) in a manufacturing firm. The study is conducted at Ensto Finland Corporation, which operates on a field of electrical systems and supplies. The paper consists of theoretical and empirical parts. The empirical part is based on weekly operating at Ensto and includes inter-firm material analysis, learning and meetings. Master Scheduling is an important module of an MPC system, since it is beneficial on transforming strategic production plans based on demand forecasting into operational schedules. Furthermore, capacity planning tools can remarkably contribute to production planning: by Rough-Cut Capacity Planning (RCCP) tool, a MS plan can be critically analyzed in terms of available key resources in real manufacturing environment. Currently, there are remarkable inefficiencies when it comes to Ensto’s practices: the system is not able to take into consideration seasonal demand and react on market changes on time; This can cause significant lost sales. However, these inefficiencies could be eliminated through the appropriate utilization of MS and RCCP tools. To utilize MS and RCCP tools in Ensto’s production environment, further testing in real production environment is required. Moreover, data accuracy, appropriate commitment to adapting and learning the new tools, and continuous developing of functions closely related to MS, such as sales forecasting, need to be ensured.

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Various regulations and customer requirements have made it necessary for Vacon Oyj to pay more attention to the environmental aspects in its processes. The main purpose of this master’s thesis project is to define how environmental aspects could be integrated into Vacon’s product development process. The aim is to find out the most important environmental aspects for the company to address, to examine how these could be taken into account during the development process and to map the critical factors that need consideration in order to ensure the successful integration of environmental aspects into the design process. Based on the customer requirements and evolving regulations the most important aspects for Vacon include minimizing the amount of harmful substances, improving the recyclability and energy efficiency of the product and moreover providing meaningful information related to these aspects. To tackle these issues, a new DfE process was developed, tasks in each phase were described and responsibilities were indicated. To ensure the success of the DfE process, management commitment, support of other processes and significant improvements in ways the information is managed are required. The developers should be provided with training and support. Environmental expertise and knowledge in-house should be developed and establishing meaningful environmental indicators is suggested.

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Seloste artikkelista: Hänninen, H., Luoranen, J., Rikala, R. and Smolander, H. 2009. Late termination of freezer storage increases the risk of autumn frost damage to Norway spruce seedlings. Silva Fennica 43 (5) : 817–830.

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Seloste artikkelista: Effects of Melampyrum extracts on the growth of axenic cultures of Cronartium flaccidum and Peridermium pini / Juha Kaitera & Heikki Nuorteva. - Julkaisussa: Silva Fennica 44 (2010) : 2, s. 197-202.

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Kirjallisuusarvostelu

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Kirjallisuusarvostelu

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Kommentti Anto Leikolan kirjoitukseen "Darwin ja elämän suunnittelu" (Tieteessä tapahtuu 8/2010).

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Seloste artikkelista: Applying the activity-based costing to cut-to-length timber harvesting and trucking / Tuomo Nurminen, Heikki Korpunen & Jori Uusitalo. - Julkaisussa: Silva Fennica 43 (2009) : 5, s. 847-870.

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Vastine / Pertti Haapala ; Vastaus / Heikki Hiilamo.