13 resultados para Transient Presence

em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland


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Tutkimuksen tavoite oli selvittää yrityksen web toiminnan rakentamisen vaiheita sekä menestyksen mittaamista. Rakennusprosessia tutkittiin viisiportaisen askelmallin avulla. Mallin askeleet ovat; arviointi, strategian muotoilu, suunnitelma, pohjapiirros ja toteutus. Arviointi- ja toteutusvaiheiden täydentämiseksi sekä erityisesti myös internet toiminnan onnistumisen mittaamisen avuksi internet toiminnan hyödyt (CRM,kommunikointi-, myynti-, ja jakelukanava hyödyt markkinoinnin kannalta) käsiteltiin. Toiminnan menestyksen arvioinnin avuksi esiteltiin myös porrasmalli internet toimintaan. Porrasmalli määrittelee kauppakulissi-, dynaaminen-, transaktio- ja e-businessportaat. Tutkimuksessa löydettiin menestystekijöitä internet toimintojen menestykselle. Nämä tekijät ovat laadukas sisältö, kiinnostavuus, viihdyttävyys, informatiivisuus, ajankohtaisuus, personoitavuus, luottamus, interaktiivisuus, käytettävyys, kätevyys, lojaalisuus, suoriutuminen, responssiivisuus ja käyttäjätiedon kerääminen. Mittarit jaettiin tutkimuksessa aktiivisuus-, käyttäytymis- ja muunnosmittareihin. Lisäksi muita mittareita ja menestysindikaattoreita esiteltiin. Nämä menestyksen elementit ja mittarit koottiin yhteen uudessa internet toimintojen menestyksenarviointimallissa. Tutkielman empiirisessä osuudessa,esitettyjä teorioita peilattiin ABB:n (ABB:n sisällä erityisesti ABB Stotz-Kontakt) web toimintaan. Apuna olivat dokumenttianalyysi sekä haastattelut. Empiirinen osa havainnollisti teoriat käytännössä ja toi ilmi mahdollisuuden teorioiden laajentamiseen. Internet toimintojen rakentamismallia voidaan käyttää myös web toimintojen kehittämiseen ja porrasmalli sopii myös nykyisten internet toimintojen arvioimiseen. Mittareiden soveltaminen käytännössä toi kuitenkin ilmi tarpeen niiden kehittämiseen ja aiheen lisätutkimukseen. Niiden tulisi olla myös aiempaatiiviimmin liitetty kokonaisvaltaisen liiketoiminnan menestyksen mittaamiseen.

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The present study focuses on two effects of the presence of a noncondensable gas on the thermal-hydraulic behavior of thecoolant of the primary circuit of a nuclear reactor in the VVER-440 geometry inabnormal situations. First, steam condensation with the presence of air was studied in the horizontal tubes of the steam generator (SG) of the PACTEL test facility. The French thermal-hydraulic CATHARE code was used to study the heat transfer between the primary and secondary side in conditions derived from preliminary experiments performed by VTT using PACTEL. In natural circulation and single-phase vapor conditions, the injection of a volume of air, equivalent to the totalvolume of the primary side of the SG at the entrance of the hot collector, did not stop the heat transfer from the primary to the secondary side. The calculated results indicate that air is located in the second half-length (from the mid-length of the tubes to the cold collector) in all the tubes of the steam generator The hot collector remained full of steam during the transient. Secondly, the potential release of the nitrogen gas dissolved in the water of the accumulators of the emergency core coolant system of the Loviisa nuclear power plant (NPP) was investigated. The author implemented a model of the dissolution and release ofnitrogen gas in the CATHARE code; the model created by the CATHARE developers. In collaboration with VTT, an analytical experiment was performed with some components of PACTEL to determine, in particular, the value of the release time constant of the nitrogen gas in the depressurization conditions representative of the small and intermediate break transients postulated for the Loviisa NPP. Such transients, with simplified operating procedures, were calculated using the modified CATHARE code for various values of the release time constant used in the dissolution and release model. For the small breaks, nitrogen gas is trapped in thecollectors of the SGs in rather large proportions. There, the levels oscillate until the actuation of the low-pressure injection pumps (LPIS) that refill the primary circuit. In the case of the intermediate breaks, most of the nitrogen gas is expelled at the break and almost no nitrogen gas is trapped in the SGs. In comparison with the cases calculated without taking into account the release of nitrogen gas, the start of the LPIS is delayed by between 1 and 1.75 h. Applicability of the obtained results to the real safety conditions must take into accountthe real operating procedures used in the nuclear power plant.

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Mitä on läsnäolo? Tämä työ määrittelee läsnäolon tietyn henkilön, laitteen tai palvelun halukkuudeksi kommunikoida. Nykyään on olemassa lukuisia läsnäolotietoa levittäviä sovelluksia, joista jokainen käyttää erilaista protokollaa tehtävän suorittamiseen. Vasta viime aikoina sovellusten kehittäjät ovat huomanneet tarpeen yhdelle sovellukselle, joka kykenee tukemaan lukuisia läsnäoloprotokollia. Session Initiation Protocol (SIP) voi levittää läsnäolotietoa muiden ominaisuuksiensa lisäksi. Kun muita protokollia käytetään vain reaaliaikaiseen viestintään ja läsnäolotiedon lähetykseen, SIP pystyy moniin muihinkin asioihin. Se on alunperin suunniteltu aloittamaan, muuttamaan ja lopettamaan osapuolien välisiä multimediaistuntoja. Arkkitehtuurin toteutus käyttää kahta Symbian –käyttöjärjestelmän perusominaisuutta: asiakas-palvelin rakennetta ja kontaktitietokantaa. Asiakaspalvelin rakenne erottaa asiakkaan protokollasta tarjoten perustan laajennettavalle usean protokollan arkkitehtuurille ja kontaktitietokanta toimii läsnäolotietojen varastona. Työn tuloksena on Symbianin käyttöjärjestelmässä toimiva läsnäoloasiakas.

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Now when the technology fast developing it is very important to control the formation of materials with better properties. In the scientific literature there is a number of works describing the influence of magnetic field on the properties and process of formation of materials. The goal of this master's thesis is to analyze the process of electrochemical synthesis of niobium oxide in the present of magnetic field, to compare properties of formed oxide films and to estimate the influence of magnetic field on the process and on the result of synthesis.

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Technology scaling has proceeded into dimensions in which the reliability of manufactured devices is becoming endangered. The reliability decrease is a consequence of physical limitations, relative increase of variations, and decreasing noise margins, among others. A promising solution for bringing the reliability of circuits back to a desired level is the use of design methods which introduce tolerance against possible faults in an integrated circuit. This thesis studies and presents fault tolerance methods for network-onchip (NoC) which is a design paradigm targeted for very large systems-onchip. In a NoC resources, such as processors and memories, are connected to a communication network; comparable to the Internet. Fault tolerance in such a system can be achieved at many abstraction levels. The thesis studies the origin of faults in modern technologies and explains the classification to transient, intermittent and permanent faults. A survey of fault tolerance methods is presented to demonstrate the diversity of available methods. Networks-on-chip are approached by exploring their main design choices: the selection of a topology, routing protocol, and flow control method. Fault tolerance methods for NoCs are studied at different layers of the OSI reference model. The data link layer provides a reliable communication link over a physical channel. Error control coding is an efficient fault tolerance method especially against transient faults at this abstraction level. Error control coding methods suitable for on-chip communication are studied and their implementations presented. Error control coding loses its effectiveness in the presence of intermittent and permanent faults. Therefore, other solutions against them are presented. The introduction of spare wires and split transmissions are shown to provide good tolerance against intermittent and permanent errors and their combination to error control coding is illustrated. At the network layer positioned above the data link layer, fault tolerance can be achieved with the design of fault tolerant network topologies and routing algorithms. Both of these approaches are presented in the thesis together with realizations in the both categories. The thesis concludes that an optimal fault tolerance solution contains carefully co-designed elements from different abstraction levels

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I en postsekulär situation har förutsättningarna för att förstå och kommunicera en kristen tradition förändrats. De etablerade religionerna kan inte längre anta att de har monopol på den ”religiösa marknaden”. Ett centralt påstående i denna studie är att en postsekulär situation, som kännetecknas av minskande medlemskap i etablerade kyrkor och en ny synlighet av alternativa religiösa uttryck, medför ett behov av att reflektera över alternativa förståelser av kristenheten i sin kontext. Denna studie frågar hur man kan meningsfullt kommunicera en kristen tradition i en postsekulär situation. Traditionellt uttryckt: hur kan man förstå kristet vittnesbörd i vår situation? Det är till denna problematik som denna studie hävdar att Stanley Hauerwas ecklesiologi tillför ett viktigt perspektiv. Hauerwas ses som ett kritiskt korrektiv till vissa synsätt som ofta möter hos Nordiska, i denna studie främst finska och svenska, lutherska teologer. Det perspektiv som utvecklas i denna studie anses vara relevant eftersom kristna kyrkor i en postsekulär situation inte längre kan anta en makt- eller majoritetsposition. Därmed uppstår ett behov av att fråga sig hur man kan förstå kristenhet som en gemenskap i en minoritetsposition som bär vittnesbörd utan samhällelig makt. Denna studie hävdar att förkroppsligande av kristna övertygelser intar en central roll i en meningsfull postsekulär förståelse av vittnesbörd.

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Kalciumjonen reglerar flera processer i celler såsom transkribering av gener, celldelning, cellernas rörlighet och celldöd. Därför har cellerna utvecklat många mekanismer för att reglera den intracellulära kalciumkoncentrationen. Kalciumkanaler spelar en viktig roll i denna regleringsprocess. TRPC-kanalerna (eng. canonical transient receptor potential) är en familj av jonkanaler med sju medlemmar (TRPC1-7) vars regleringsmekanismer och fysiologiska roller är varierande. TRPC2-kanalens fysiologiska signifikans, samt hur kanalen regleras, är dåligt karakteriserad. För första gången, rapporterar vi närvaron av TRPC2 kanalen i råttans sköldkörtelceller samt primära sköldkörtelceller från råtta. Hos gnagare har TRPC2 antagits vara exklusivt uttryckt i det vomeronasala organet. För att undersöka den fysiologiska betydelsen av kanalen, har vi utvecklat stabila celler med nedreglerat TRPC2 (shTRPC2) m.h.a. shRNA-teknik. Nedreglering av TRPC2 resulterade i stora skillnader i flera viktiga cellulära funktioner och i regleringen av sköldkörtelcellernas cellsignalering. Nedreglering av TRPC2 orsakade minskad agonist-beroende frigivning av kalcium från det endoplasmatiska nätverket, samt minskat agonist-beroende inflöde av extracellulärt kalcium, men ökade det basala kalciuminflödet. Uttrycket av PKCβ1 och PKCδ, SERCA-aktiviteten och kalciumhalten i det endoplasmatiska nätverket minskade i shTRPC2 celler. Kommunikation mellan kalcium- och cAMP-signalering påvisades vara TRPC2-beroende, vilket visades reglera uttrycket av TSH-receptorn. Vi undersökte också betydelsen av TRPC2 kanalen i reglering av sköldkörtelcellers proliferation, migration, vidhäftning och invasion; processer som alla var dämpade i shTRPC2 celler. Samamnfattningsvis påvisade dessa resultat en ny och viktig fysiologisk betydelse för TRPC2 kanalerna.

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The evolution of our society is impossible without a constant progress in life-important areas such as chemical engineering and technology. Innovation, creativity and technology are three main components driving the progress of chemistry further towards a sustainable society. Biomass, being an attractive renewable feedstock for production of fine chemicals, energy-rich materials and even transportation fuels, captures progressively new positions in the area of chemical technology. Knowledge of heterogeneous catalysis and chemical technology applied to transformation of biomass-derived substances will open doors for a sustainable economy and facilitates the discovery of novel environmentally-benign processes which probably will replace existing technologies in the era of biorefinary. Aqueous-phase reforming (APR) is regarded as a promising technology for production of hydrogen and liquids fuels from biomass-derived substances such as C3-C6 polyols. In the present work, aqueous-phase reforming of glycerol, xylitol and sorbitol was investigated in the presence of supported Pt catalysts. The catalysts were deposited on different support materials, including Al2O3, TiO2 and carbons. Catalytic measurements were performed in a laboratory-scale continuous fixedbed reactor. An advanced analytical approach was developed in order to identify reaction products and reaction intermediates in the APR of polyols. The influence of the substrate structure on the product formation and selectivity in the APR reaction was also investigated, showing that the yields of the desired products varied depending on the substrate chain length. Additionally, the influence of bioethanol additive in the APR of glycerol and sorbitol was studied. A reaction network was advanced explaining the formation of products and key intermediates. The structure sensitivity in the aqueous-phase reforming reaction was demonstrated using a series of platinum catalysts supported on carbon with different Pt cluster sizes in the continuous fixed-bed reactor. Furthermore, a correlation between texture physico-chemical properties of the catalysts and catalytic data was established. The effect of the second metal (Re, Cu) addition to Pt catalysts was investigated in the APR of xylitol showing a superior hydrocarbon formation on PtRe bimetallic catalysts compared to monometallic Pt. On the basis of the experimental data obtained, mathematical modeling of the reaction kinetics was performed. The developed model was proven to successfully describe experimental data on APR of sorbitol with good accuracy.

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Male germ cell differentiation, spermatogenesis is an exceptional developmental process that produces a massive amount of genetically unique spermatozoa. The complexity of this process along with the technical limitations in the germline research has left many aspects of spermatogenesis poorly understood. Post-meiotic haploid round spermatids possess the most complex transcriptomes of the whole body. Correspondingly, efficient and accurate control mechanisms are necessary to deal with the huge diversity of transcribed RNAs in these cells. The high transcriptional activity in round spermatids is accompanied by the presence of an uncommonly large cytoplasmic ribonucleoprotein granule, called the chromatoid body (CB) that is conjectured to participate in the RNA post-transcriptional regulation. However, very little is known about the possible mechanisms of the CB function. The development of a procedure to isolate CBs from mouse testes was this study’s objective. Anti-MVH immunoprecipitation of cross-linked CBs from a fractionated testicular cell lysate was optimized to yield considerable quantities of pure and intact CBs from mice testes. This protocol produced reliable and reproducible data from the subsequent analysis of CB’s protein and RNA components. We found that the majority of the CB’s proteome consists of RNA-binding proteins that associate functionally with different pathways. We also demonstrated notable localization patterns of one of the CB transient components, SAM68 and showed that its ablation does not change the general composition or structure of the CB. CB-associated RNA analysis revealed a strong accumulation of PIWI-interacting RNAs (piRNAs), mRNAs and long non-coding RNAs (lncRNAs) in the CB. When the CB transcriptome and proteome analysis results were combined, the most pronounced molecular functions in the CB were related to piRNA pathway, RNA post-transcriptional processing and CB structural scaffolding. In addition, we demonstrated that the CB is a target for the main RNA flux from the nucleus throughout all steps of round spermatid development. Moreover, we provided preliminary evidence that those isolated CBs slice target RNAs in vitro in an ATPdependent manner. Altogether, these results make a strong suggestion that the CB functions involve RNA-related and RNA-mediated mechanisms. All the existing data supports the hypothesis that the CB coordinates the highly complex haploid transcriptome during the preparation of the male gametes for fertilization. Thereby, this study provides a fundamental basis for the future functional analyses of ribonucleoprotein granules and offers also important insights into the mechanisms governing male fertility.

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Nowadays advanced simulation technologies of semiconductor devices occupies an important place in microelectronics production process. Simulation helps to understand devices internal processes physics, detect new effects and find directions for optimization. Computer calculation reduces manufacturing costs and time. Modern simulation suits such as Silcaco TCAD allow simulating not only individual semiconductor structures, but also these structures in the circuit. For that purpose TCAD include MixedMode tool. That tool can simulate circuits using compact circuit models including semiconductor structures with their physical models. In this work, MixedMode is used for simulating transient current technique setup, which include detector and supporting electrical circuit. This technique was developed by RD39 collaboration project for investigation radiation detectors radiation hard properties.

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Asymmetric synthesis using modified heterogeneous catalysts has gained lots of interest in the production of optically pure chemicals, such as pharmaceuticals, nutraceuticals, fragrances and agrochemicals. Heterogeneous modified catalysts capable of inducing high enantioselectivities are preferred in industrial scale due to their superior separation and handling properties. The topic has been intensively investigated both in industry and academia. The enantioselective hydrogenation of ethyl benzoylformate (EBF) to (R)-ethyl mandelate over (-)-cinchonidine (CD)-modified Pt/Al2O3 catalyst in a laboratory-scale semi-batch reactor was studied as a function of modifier concentration, reaction temperature, stirring rate and catalyst particle size. The main product was always (R)-ethyl mandelate while small amounts of (S)-ethyl mandelate were obtained as by product. The kinetic results showed higher enantioselectivity and lower initial rates approaching asymptotically to a constant value as the amount of modifier was increased. Additionally, catalyst deactivation due to presence of impurities in the feed was prominent in some cases; therefore activated carbon was used as a cleaning agent of the raw material to remove impurities prior to catalyst addition. Detailed characterizations methods (SEM, EDX, TPR, BET, chemisorption, particle size distribution) of the catalysts were carried out. Solvent effects were also studied in the semi-batch reactor. Solvents with dielectric constant (e) between 2 and 25 were applied. The enantiomeric excess (ee) increased with an increase of the dielectric coefficient up to a maximum followed by a nonlinear decrease. A kinetic model was proposed for the enantioselectivity dependence on the dielectric constant based on the Kirkwood treatment. The non-linear dependence of ee on (e) successfully described the variation of ee in different solvents. Systematic kinetic experiments were carried out in the semi-batch reactor. Toluene was used as a solvent. Based on these results, a kinetic model based on the assumption of different number of sites was developed. Density functional theory calculations were applied to study the energetics of the EBF adsorption on pure Pt(1 1 1). The hydrogenation rate constants were determined along with the adsorption parameters by non-linear regression analysis. A comparison between the model and the experimental data revealed a very good correspondence. Transient experiments in a fixed-bed reactor were also carried out in this work. The results demonstrated that continuous enantioselective hydrogenation of EBF in hexane/2-propanol 90/10 (v/v) is possible and that continuous feeding of (-)-cinchonidine is needed to maintain a high steady-state enantioselectivity. The catalyst showed a good stability and high enantioselectivity was achieved in the fixed-bed reactor. Chromatographic separation of (R)- and (S)-ethyl mandelate originating from the continuous reactor was investigated. A commercial column filled with a chiral resin was chosen as a perspective preparative-scale adsorbent. Since the adsorption equilibrium isotherms were linear within the entire investigated range of concentrations, they were determined by pulse experiments for the isomers present in a post-reaction mixture. Breakthrough curves were measured and described successfully by the dispersive plug flow model with a linear driving force approximation. The focus of this research project was the development of a new integrated production concept of optically active chemicals by combining heterogeneous catalysis and chromatographic separation technology. The proposed work is fundamental research in advanced process technology aiming to improve efficiency and enable clean and environmentally benign production of enantiomeric pure chemicals.

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Tavallisten hapetusmenetelmien sijasta kehittyneitä hapetusmenetelmiä (AOP) on kehitetty yhä enemmän, jotta hapetusprosessista tulisi kannattavampi, tehokkaampi, ympäristöystävällisempi ja sitä voitaisiin hyödyntää laajalti eri paikoissa. Uusi teknologia, joka käyttää otsonia ja hydroksyyliradikaalia sähköimpulssien kanssa, on yksi mahdollinen tehokkaampi vedenkäsittelymentelmä. Kyseistä menetelmää kutsutaa pulsed corona discharge (PCD) -menetelmäksi, joka käyttää prosessissa muodostuvia otsonia ja hydroksyyliradikaalia hapettavina tekijöinä. Tässä työssä tutkittiin nitraatin muodostumista vedessä, kun vettä käsiteltiin PCD-laitteessa ja, kun oksalaatti- ja formaatti-ioneja oli sekoittuneina veteen. Nitraatteja muodostuu PCD–laitteessa veteen, kun ilman typpi reagoi hapettimina toimivien otsonin ja hydroksyyliradikaalin kanssa. Aiemmissa tutkimuksissa nitraatin muodostumisen on todistettu parantuvan, kun karboksyylihapot muurahais- ja oksaalihappo ovat sekoittuneina veteen. Tässä tutkimuksessa tarkoituksena oli tutkia, miten formaatti- ja oksalaatti-ionien, joiden pitoisuudet olivat 0 ppm, 50 ppm ja 100 ppm, läsnäolo vedessä vaikuttaa nitraatin muodostumiseen. PCD-kokeista saadut näytteet analysoitiin ionikromatografilla. Kyseisessä tutkimuksessa nitraatin muodostuminen oli samansuuruista jokaisessa kokeessa hapetusajan kasvaessa samalla, kun otettujen näytteiden pH-arvot laskivat. Tuloksena voitiin pitää sitä, ettei formaatti- tai oksalaatti-ioneilla ollut vaikutusta nitraatti-ionien muodostumiseen.

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Increasingly growing share of distributed generation in the whole electrical power system’s generating system is currently a worldwide tendency, driven by several factors, encircling mainly difficulties in refinement of megalopolises’ distribution networks and its maintenance; widening environmental concerns adding to both energy efficiency approaches and installation of renewable sources based generation, inherently distributed; increased power quality and reliability needs; progress in IT field, making implementable harmonization of needs and interests of different-energy-type generators and consumers. At this stage, the volume, formed by system-interconnected distributed generation facilities, have reached the level of causing broad impact toward system operation under emergency and post-emergency conditions in several EU countries, thus previously implementable approach of their preliminary tripping in case of a fault, preventing generating equipment damage and disoperation of relay protection and automation, is not applicable any more. Adding to the preceding, withstand capability and transient electromechanical stability of generating technologies, interconnecting in proximity of load nodes, enhanced significantly since the moment Low Voltage Ride-Through regulations, followed by techniques, were introduced in Grid Codes. Both aspects leads to relay protection and auto-reclosing operation in presence of distributed generation generally connected after grid planning and construction phases. This paper proposes solutions to the emerging need to ensure correct operation of the equipment in question with least possible grid refinements, distinctively for every type of distributed generation technology achieved its technical maturity to date and network’s protection. New generating technologies are equivalented from the perspective of representation in calculation of initial steady-state short-circuit current used to dimension current-sensing relay protection, and widely adopted short-circuit calculation practices, as IEC 60909 and VDE 0102. The phenomenon of unintentional islanding, influencing auto-reclosing, is addressed, and protection schemes used to eliminate an sustained island are listed and characterized by reliability and implementation related factors, whereas also forming a crucial aspect of realization of the proposed protection operation relieving measures.