10 resultados para area of the circle
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
In the paper machine, it is not a desired feature for the boundary layer flows in the fabric and the roll surfaces to travel into the closing nips, creating overpressure. In this thesis, the aerodynamic behavior of the grooved roll and smooth rolls is compared in order to understand the nip flow phenomena, which is the main reason why vacuum and grooved roll constructions are designed. A common method to remove the boundary layer flow from the closing nip is to use the vacuum roll construction. The downside of the use of vacuum rolls is high operational costs due to pressure losses in the vacuum roll shell. The deep grooved roll has the same goal, to create a pressure difference over the paper web and keep the paper attached to the roll or fabric surface in the drying pocket of the paper machine. A literature review revealed that the aerodynamic functionality of the grooved roll is not very well known. In this thesis, the aerodynamic functionality of the grooved roll in interaction with a permeable or impermeable wall is studied by varying the groove properties. Computational fluid dynamics simulations are utilized as the research tool. The simulations have been performed with commercial fluid dynamics software, ANSYS Fluent. Simulation results made with 3- and 2-dimensional fluid dynamics models are compared to laboratory scale measurements. The measurements have been made with a grooved roll simulator designed for the research. The variables in the comparison are the paper or fabric wrap angle, surface velocities, groove geometry and wall permeability. Present-day computational and modeling resources limit grooved roll fluid dynamics simulations in the paper machine scale. Based on the analysis of the aerodynamic functionality of the grooved roll, a grooved roll simulation tool is proposed. The smooth roll simulations show that the closing nip pressure does not depend on the length of boundary layer development. The surface velocity increase affects the pressure distribution in the closing and opening nips. The 3D grooved roll model reveals the aerodynamic functionality of the grooved roll. With the optimal groove size it is possible to avoid closing nip overpressure and keep the web attached to the fabric surface in the area of the wrap angle. The groove flow friction and minor losses play a different role when the wrap angle is changed. The proposed 2D grooved roll simulation tool is able to replicate the grooved aerodynamic behavior with reasonable accuracy. A small wrap angle predicts the pressure distribution correctly with the chosen approach for calculating the groove friction losses. With a large wrap angle, the groove friction loss shows too large pressure gradients, and the way of calculating the air flow friction losses in the groove has to be reconsidered. The aerodynamic functionality of the grooved roll is based on minor and viscous losses in the closing and opening nips as well as in the grooves. The proposed 2D grooved roll model is a simplification in order to reduce computational and modeling efforts. The simulation tool makes it possible to simulate complex paper machine constructions in the paper machine scale. In order to use the grooved roll as a replacement for the vacuum roll, the grooved roll properties have to be considered on the basis of the web handling application.
Resumo:
Targeted measures bring the greatest benefits for environmental protection in agriculture final report of the TEHO Plus project (2011–2014). Particular priority areas of the project activities included creating a training package for agri-environment advisers and testing it, farm-specific advisory services and exploitation of experiences of advice provision, putting together an information package of agri-environment issues, farm-level experiments, and development of water quality monitoring. The recommendations issued by advisers on targeting environmental measures were based on utilising geographical information material and nutrient balances. The project was implemented in cooperation by Southwest Finland Centre for Economic Development, Transport and the Environment, MTK-Satakunta and MTK-Varsinais-Suomi. The project received funding from the Ministry of Agriculture and Forestry and the Ministry of the Environment. Participating farmers, with whom environmental advice was developed and experiments were carried out, were important partners for the project. The operating area of the project was Satakunta and Varsinais-Suomi in Southwest Finland, but its outcomes can be exploited nationally. A national perspective was ensured by close cooperation with actors in different provinces. This final report describes project experiences and outcomes including environmental advisory services, training of agri-environmental advisers, farm visits and the feedback received from farmers on agri-environmental advice, development of water quality monitoring, experiments and project work.
Resumo:
Digital reproduction, The National Library of Finland, Centre for Preservation and Digitisation, Mikkeli
Resumo:
The conference promoting the objectives of the international European Landscape Convention (ELC) was held on 7-9 September 2011 in Inari. The primary aim of the conference was to increase awareness of the ELC and the prospects and requirements it brings to practical planning work, especially at the municipal level. The conference speakers included top experts from Sweden, Norway, Finland, France, Holland and Catalonia. This report is a collection of articles written by the experts in the ELC conference. The report is available in five languages: Finnish, Swedish, Norwegian, Northern Sámi and English. The common characteristics of the North Calotte area, such as the magnificent riverside scenery and the beautiful fell landscapes formed by the Sámi culture and reindeer management are broadly reflected in the environment. Alongside the traditional forms of land use, many other livelihoods and forms of land use now need to be accommodated in the area. Tourism, energy production, mining industry and new infrastructure create new and manifold challenges to the authorities in charge of land use in these areas. Municipalities need information and support for versatile planning in the future, so that the unique and valuable characteristics of the North can be preserved. Landscape protection and management in the landscape areas is executed through areal and land use planning, mainly through town planning and the creation of landscape management plans. The municipalities in the North Calotte region have their own partly divergent methods and practices, based on the various land use processes are executed. The municipalities and inhabitants have a great interest in preserving and protecting their living environment and maintaining and increasing the appeal of the area. Landscape is viewed as one of the most significant appealing factors that cannot be lost. The increasing land use in municipalities, for example due to energy production, mining industry and increasing tourism, create a need for more multidimensional planning. The reconciliation of the wishes of different interest groups, and traditional and new livelihoods will not be easy. Conflict is inevitable. This will lead to a greater need to engage local bodies to the planning processes right from the start of the projects. Close cooperation between different administrative branches, operators, local bodies and landscape research promote the objectives of the convention. To ensure that the work continues, a landscape co-operation group is planned to be established in the North Calotte area. It´s main task is to promote and develop landscape policy in the area.
Resumo:
Tutkimuksen tavoitteena on selvittää tarkoituksenmukaisin etabloitumismenetelmä teräsyhtiön kansainvälistymisessä Pietarin markkinoille. Vaikka kansainvälistymistä onkin tutkittu paljon, kyseisen kontekstin erityispiirteisiin on aiemmissa tutkimuksissa kiinnitetty vain vähän huomiota. Kansainvälistymisteorioista työhön valittiin John Dunningin eklektinen paradigma sekä Uppsala-malli. Etabloitumismenetelmän valintaa puolestaan tarkastellaan eri vaihtoehtojen kautta, jotka kattavat viennin, suorat ulkomaan investoinnit, sopimusjärjestelyt sekä yhteisyrityksen. Valintaa selitetään taustalla vaikuttavien tekijöiden sekä kansainvälistymisprosessin kautta. Kohteena olevan markkina-alueen potentiaalin, ongelmien sekä yrityksen kilpailuetujen arvioinnin jälkeen ehdotetaan optimaalista ratkaisua. Omat haasteensa operaatiomuodon valintaan luovat potentiaalinen mutta haastava kohdemarkkina-alue sekä yrityksen sisäiset tekijät. Kontekstiin parhaiten sopivaksi etabloitumismenetelmäksi esitetään aloittamista välittömällä viennillä asiakkaiden etsimiseksi ja suhteiden luomiseksi. Kun asiakkuuksia alueella on riittävästi, myyntikonttorin perustaminen Pietarin lähelle nähdään tarkoituksenmukaisena paikallisen läsnäolon lisäämiseksi. Empiirinen data kattaa kahdeksan asiantuntijahaastattelua, jotka yhdessä muun lähdeaineiston kanssa rakentavat perustan empiirisille tuloksille. Tutkimuksen tulokset tarjoavat yritykselle perustellun ratkaisuehdotuksen siitä, kuinka Pietarin markkinoille tulisi etabloitua.
Resumo:
This report examines the human impact on the subarctic environment of the joint border area of Norway, Finland and Russia. The aim is to present the current state and recent changes that have taken place in the region. The main threat to the environment is the Pechenganikel mining and metallurgical industrial combine in the towns of Nikel and Zapolyarny in the Kola Peninsula. Emissions from this complex include high levels of heavy metals, persistent organic pollutants and sulfur dioxide. Pollution, along with climate change, water level regulation and other anthropogenic effects, has affected the aquatic ecosystems in the joint border area. The main heavy metals in the area are copper and nickel, the highest concentrations of which are measured near the combine. Direct discharge of sewage into the river continues and airborne heavy metal particles are also deposited to areas farther away. Climate changeinduced increase in temperature and precipitation in the Kola Peninsula is evident. Water level regulation with seven hydropower plants in the Pasvik River have changed it into a series of lakes and lake-like reservoirs. This report discusses modelling, which was enabled to estimate the effect of climate change on Lake Inarijärvi and the Pasvik River hydrology, water level fluctuation and ecology and to follow the sulfur dioxide emissions emitted from the Pechenganikel. Effects of pollution on the nature and concentrations of the main pollutants were studied and climate change in the border area and its effects on the ecology were estimated. Also the effects of water level regulation on the ecological status of the aquatic ecosystems were addressed.
Resumo:
Teema: Yliopistohistoria.