73 resultados para Ceramic engineering


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this thesis, cleaning of ceramic filter plates clogged by iron oxides was studied. Oxalic acid is considered as the most effective cleaning agent for the plates fouled by iron oxides, but when using oxalic acid, sparingly soluble calcium oxalate may be formed and it can blind the filter media. Suitability of another chemical for cleaning the plates clogged by iron oxides was studied in this thesis. The literature part was mostly about the properties of the chemical, about its reactions, industrial uses, safety issues etc. In the experimental part, the efficiency of the chemical for cleaning of the ceramic plates clogged by iron oxides was studied. Two kinds of plates were used in the experiments; the others were clogged by hematite and the others by magnetite. Both soaking and flow-through experiments were done. A suitable concentration, pH and temperature were tried to find in the experiments. Also the effect of ultrasound was studied. The efficiency of the cleaning was examined by measuring the permeability of the plates during the experiments. ICP-OES analysis was performed for determining the amount of dissolved iron in the washing solution. Some experiments were also done with oxalic acid. The results from the oxalic acid experiments were compared to the results from the experiments with the other chemical. In the experiments with the other chemical, the permeability increased more and the amounts of dissolved iron were larger. According to the results from the experiments, the method of application of the washing solutions had an impact on the washing results.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Systems suppliers are focal actors in mechanical engineering supply chains, in between general contractors and component suppliers. This research concentrates on the systems suppliers’ competitive flexibility, as a competitive advantage that the systems supplier gains from independence from the competitive forces of the market. The aim is to study the roles that power, dependence relations, social capital, and interorganizational learning have on the competitive flexibility. Research on this particular theme is scarce thus far. The research method applied here is the inductive multiple case study. Interviews from four case companies were used as main source of the qualitative data. The literature review presents previous literature on subcontracting, supply chain flexibility, supply chain relationships, social capital and interorganizational learning. The result of this study are seven propositions and consequently a model on the effects that the dominance of sales of few customers, power of competitors, significance of the manufactured system in the end product, professionalism in procurement and the significance of brand products in the business have on the competitive flexibility. These relationships are moderated by either social capital or interorganizational learning. The main results obtained from this study revolve around social capital and interorganizational learning, which have beneficial effects on systems suppliers’ competitive flexibility, by moderating the effects of other constructs of the model. Further research on this topic should include quantitative research to provide the extent to which the results can be reliably generalized. Also each construct of the model gives possible focus for more thorough research.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work proposes a method of visualizing the trend of research in the field of ceramic membranes from 1999 to 2006. The presented approach involves identifying problems encountered during research in the field of ceramic membranes. Patents from US patent database and articles from Science Direct(& by ELSEVIER was analyzed for this work. The identification of problems was achieved with software Knowledgist which focuses on the semantic nature of a sentence to generate series of subject action object structures. The identified problems are classified into major research issues. This classification was used for the visualization of the intensity of research. The image produced gives the relation between the number of patents, with time and the major research issues. The identification of the most cited papers which strongly influence the research of the previously identified major issues in the given field was also carried out. The relations between these papers are presented using the metaphor of social network. The final result of this work are two figures, a diagram showing the change in the studied problems a specified period of time and a figure showing the relations between the major papers and groups of the problems

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aiheen laajempi artikkeli on julkaistu konferenssi-CD:llä.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this study was to investigate the nature of co-operation between a project owner and an outside engineering consultant in combined heat and power plant implementation projects. Moreover, as another focal subject of the study was to familiarize the purchasing behavior of the energy producer and how an outside engineering consultant participated into different stages of the purchasing process. The study was carried out as a multiple case study including altogether six Finnish power plant implementation projects that had been taken into commercial use during 1995 – 2015. By adjusting the findings of empirical interview data and comparing those to the theoretical framework concerning, among others, Finnish energy production, engineering consulting businesses, delivery methods of construction project and finally the purchasing process, it can be concluded that especially in the power plant implementation projects in the past have a great influence to decisions made during the project. The role of the main engineering consultant is to act as an assistant, who helps to achieve the project goals successfully rather than an advisor who only knows how the project should be conducted. At least in these five project cases this was the case, meaning that the final decision power always remaining with project owner.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Research focus of this thesis is to explore options for building systems for business critical web applications. Business criticality here includes requirements for data protection and system availability. The focus is on open source software. Goals are to identify robust technologies and engineering practices to implement such systems. Research methods include experiments made with sample systems built around chosen software packages that represent certain technologies. The main research focused on finding a good method for database data replication, a key functionality for high-availability, database-driven web applications. Research included also finding engineering best practices from books written by administrators of high traffic web applications. Experiment with database replication showed, that block level synchronous replication offered by DRBD replication software offered considerably more robust data protection and high-availability functionality compared to leading open source database product MySQL, and its built-in asynchronous replication. For master-master database setups, block level replication is more recommended way to build high-availability into the system. Based on thesis research, building high-availability web applications is possible using a combination of open source software and engineering best practices for data protection, availability planning and scaling.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Segmentointi on perinteisesti ollut erityisesti kuluttajamarkkinoinnin työkalu, mutta siirtymä tuotteista palveluihin on lisännyt segmentointitarvetta myös teollisilla markkinoilla. Tämän tutkimuksen tavoite on löytää selkeästi toisistaan erottuvia asiakasryhmiä suomalaisen liikkeenjohdon konsultointiyritys Synocus Groupin tarjoaman case-materiaalin pohjalta. K-means-klusteroinnin avulla löydetään kolme potentiaalista markkinasegmenttiä perustuen siihen, mitkä tarjoamaelementit 105 valikoitua suomalaisen kone- ja metallituoteteollisuuden asiakasta ovat maininneet tärkeimmiksi. Ensimmäinen klusteri on hintatietoiset asiakkaat, jotka laskevat yksikkökohtaisia hintoja. Toinen klusteri koostuu huolto-orientoituneista asiakkaista, jotka laskevat tuntikustannuksia ja maksimoivat konekannan käyttötunteja. Tälle kohderyhmälle kannattaisi ehkä markkinoida teknisiä palveluja ja huoltosopimuksia. Kolmas klusteri on tuottavuussuuntautuneet asiakkaat, jotka ovat kiinnostuneita suorituskyvyn kehittämisestä ja laskevat tonnikohtaisia kustannuksia. He tavoittelevat alempia kokonaiskustannuksia lisääntyneen suorituskyvyn, pidemmän käyttöiän ja alempien huoltokustannusten kautta.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Työn tarkoituksena on selvittää miten sähköistä kysynnän herättämistä voidaan hyödyntää Mantsinen Group Ltd Oy:ssä siten, että sillä pystytään tukemaan myyntiä. Lisäksi sähköisen kysynnän herättämisen tehokkuutta tutkitaan, jotta saadaan selville onko se kannattavaa ja kuinka hyvin se sopii yritykselle. Kysynnän herättämisjärjestelmän käyttö on määritelty kirjallisuuteen perustuen ja sen jälkeen järjestelmän käyttö on aloitettu. Sähköisen kysynnän herättämisen tehokkuus mitataan kolmen kuukauden tarkastelujakson todellisella datalla. Sähköisen kysynnän herättämisen sopivuutta arvioidaan perustuen sen kustannustehokkuuteen ja tuloksiin. Työn tulokset osoittavat, että sähköinen kysynnän herättäminen on kannattavaa ja se sopii yritykselle. Sillä voidaan parhaiten tukea myyntiä järjestelmän tuottaessa laadukkaita myyntimahdollisuuksia tasaisena virtana myynnille. Myös aiemmin manuaalisesti tehtyjä työtehtäviä voidaan automatisoida ja näin vähentää myyjien työtaakkaa.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Vätning av fasta ytor är ett viktigt fenomen i såväl naturen som i en lång rad av industriella tillämpningar. Det är allmänt känt att vätningen av en fast yta styrs av ytans kemi samt struktur. Målsättningen med avhandlingen var att studera hur kemisk heterogenitet och ytråhet på nanometernivå påverkar vätningsegenskaperna hos en fast yta. Ytorna som studerades var titandioxid-baserade kerama ytor som framställdes med hjälp av en sol-gel process. Vätningstudierna utfördes genom kontaktvinkelmätningar, vilket innebär att man mäter vinkeln som vätska/luft-gränsskiktet hos en vätskedroppe bildar mot en fast yta. Ytråheten hos materialen studerades främst genom atomkraftsmikroskopi (AFM). I AFM detekteras ytans struktur av en mycket skarp nål som skannar ytan. Resultaten i avhandlingen kunde framgångsrikt modelleras med existerande teorier för vätning av heterogena ytor.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis is done as a part of project called FuncMama that is a project between Technical Research Centre of Finland (VTT), Oulu University (OY), Lappeenranta University of Technology (LUT) and Finnish industrial partners. Main goal of the project is to manufacture electric and mechanical components from mixed materials using laser sintering. Aim of this study was to create laser sintered pieces from ceramic material and monitor the sintering event by using spectrometer. Spectrometer is a device which is capable to record intensity of different wavelengths in relation with time. In this study the monitoring of laser sintering was captured with the equipment which consists of Ocean Optics spectrometer, optical fiber and optical lens (detector head). Light from the sintering process hit first to the lens system which guides the light in to the optical fibre. Optical fibre transmits the light from the sintering process to the spectrometer where wavelengths intensity level information is detected. The optical lens of the spectrometer was rigidly set and did not move along with the laser beam. Data which was collected with spectrometer from the laser sintering process was converted with Excel spreadsheet program for result’s evaluation. Laser equipment used was IPG Photonics pulse fibre laser. Laser parameters were kept mainly constant during experimental part and only sintering speed was changed. That way it was possible to find differences in the monitoring results without fear of too many parameters mixing together and affecting to the conclusions. Parts which were sintered had one layer and size of 5 x 5 mm. Material was CT2000 – tape manufactured by Heraeus which was later on post processed to powder. Monitoring of different sintering speeds was tested by using CT2000 reference powder. Moreover tests how different materials effect to the process monitoring were done by adding foreign powder Du Pont 951 which had suffered in re-grinding and which was more reactive than CT2000. By adding foreign material it simulates situation where two materials are accidently mixed together and it was studied if that can be seen with the spectrometer. It was concluded in this study that with the spectrometer it is possible to detect changes between different laser sintering speeds. When the sintering speed is lowered the intensity level of light is higher from the process. This is a result of higher temperature at the sintering spot and that can be noticed with the spectrometer. That indicates it could be possible to use spectrometer as a tool for process observation and support the idea of having system that can help setting up the process parameter window. Also important conclusion was how well the adding of foreign material could be seen with the spectrometer. When second material was added a significant intensity level raise could be noticed in that part where foreign material was mixed. That indicates it is possible to see if there are any variations in the material or if there are more materials mixed together. Spectrometric monitoring of laser sintering could be useful tool for process window observation and temperature controlling of the sintering process. For example if the process window for specific material is experimentally determined to get wanted properties and satisfying sintering speed. It is possible if the data is constantly recorded that the results can show faults in the part texture between layers. Changes between the monitoring data and the experimentally determined values can then indicate changes in the material being generated by material faults or by wrong process parameters. The results of this study show that spectrometer could be one possible tool for monitoring. But to get in that point where this all can be made possible much more researching is needed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Earlier management studies have found a relationship between managerial qualities and subordinate impacts, but the effect of managers‘ social competence on leader perceptions has not been solidly established. To fill the related research gap, the present work embarks on a quantitative empirical effort to identify predictors of successful leadership. In particular, this study investigates relationships between perceived leader behavior and three selfreport instruments used to measure managerial capability: 1) the WOPI Work Personality Inventory, 2) Raven‘s general intelligence scale, and 3) the Emotive Communication Scale (ECS). This work complements previous research by resorting to both self-reports and other-reports: the results acquired from the managerial sample are compared to subordinate perceptions as measured through the ECS other-report and the WOPI360 multi-source appraisal. The quantitative research is comprised of a sample of 8o superiors and 354 subordinates operating in eight Finnish organizations. The strongest predictive value emerged from the ECS self- and other-reports and certain personality dimensions. In contrast, supervisors‘ logical intelligence did not correlate with leadership perceived as socially competent by subordinates. 16 of the superiors rated as most socially competent by their subordinates were selected for case analysis. Their qualitative narratives evidence the role of life history and post-traumatic growth in developing managerial skills. The results contribute to leadership theory in four ways. First, the ECS self-report devised for this research offers a reliable scale for predicting socially competent leader ability. Second, the work identifies dimensions of personality and emotive skills that can be considered predictors of managerial ability and benefited from in leader recruitment and career planning. Third, the Emotive Communication Model delineated on the basis of the empirical data allows for a systematic design and planning of communication and leadership education. Fourth, this workfurthers understanding of personal growth strategies and the role of life history in leader development and training. Finally, this research advances educational leadership by conceptualizing and operationalizing effective managerial communications. The Emotive Communication Model devised directs the pedagogic attention in engineering to assertion, emotional availability and inspiration skills. The proposed methodology addresses classroom management strategies drawing from problem-based learning, student empowerment, collaborative learning, and so-called socially competent teachership founded on teacher immediacy and perceived caring, all constituting strategies moving away from student compliance and teacher modelling. The ultimate educational objective embraces the development of individual engineers and organizational leaders that not only possess traditional analytical and technical expertise and substantive knowledge but are intelligent also creatively, practically, and socially.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Filtration is a widely used unit operation in chemical engineering. The huge variation in the properties of materials to be ltered makes the study of ltration a challenging task. One of the objectives of this thesis was to show that conventional ltration theories are di cult to use when the system to be modelled contains all of the stages and features that are present in a complete solid/liquid separation process. Furthermore, most of the ltration theories require experimental work to be performed in order to obtain critical parameters required by the theoretical models. Creating a good overall understanding of how the variables a ect the nal product in ltration is somewhat impossible on a purely theoretical basis. The complexity of solid/liquid separation processes require experimental work and when tests are needed, it is advisable to use experimental design techniques so that the goals can be achieved. The statistical design of experiments provides the necessary tools for recognising the e ects of variables. It also helps to perform experimental work more economically. Design of experiments is a prerequisite for creating empirical models that can describe how the measured response is related to the changes in the values of the variable. A software package was developed that provides a ltration practitioner with experimental designs and calculates the parameters for linear regression models, along with the graphical representation of the responses. The developed software consists of two software modules. These modules are LTDoE and LTRead. The LTDoE module is used to create experimental designs for di erent lter types. The lter types considered in the software are automatic vertical pressure lter, double-sided vertical pressure lter, horizontal membrane lter press, vacuum belt lter and ceramic capillary action disc lter. It is also possible to create experimental designs for those cases where the variables are totally user de ned, say for a customized ltration cycle or di erent piece of equipment. The LTRead-module is used to read the experimental data gathered from the experiments, to analyse the data and to create models for each of the measured responses. Introducing the structure of the software more in detail and showing some of the practical applications is the main part of this thesis. This approach to the study of cake ltration processes, as presented in this thesis, has been shown to have good practical value when making ltration tests.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this master’s thesis is to study how Agile method (Scrum) and open source software are utilized to produce software for a flagship product in a complex production environment. The empirical case and the used artefacts are taken from the Nokia MeeGo N9 product program, and from the related software program, called as the Harmattan. The single research case is analysed by using a qualitative method. The Grounded Theory principles are utilized, first, to find out all the related concepts from artefacts. Second, these concepts are analysed, and finally categorized to a core category and six supported categories. The result is formulated as the operation of software practices conceivable in circumstances, where the accountable software development teams and related context accepts a open source software nature as a part of business vision and the whole organization supports the Agile methods.