[Tripartita op. 5]

Soitinnus: orkesteri.

[Tripartita] : [osat 2. Adagio ja 1. Scherzo]

Soitinnus: orkesteri.

Dia

Digitoitu 15. 10. 2007.

Computational and Experimental Investigation of the Grooved Roll in Paper Machine Environment

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.

Branding and Marketing Communications of Lifestyle Prescription Drugs in a Strict Legislative Environment

This thesis discusses the different possibilities to brand and promote a patented prescription lifestyle drug through different marketing communications practices. This thesis aims in explaining how branding procedures can be built in circumstances, where the legislative environment is strickt and furthermore, the environment consists of both B-to-B and B-to-C market characteristics simultaneously.

De sulphate ammoniacae [et] magnesiae

Dedicatio: Johannes Agricola.

Historia Regiae Academiae Aboensis

Invocatio: I.N.J.C.

Om jordens svedande och kyttande i Finland

Invocatio: M.G.H.

Suomen tieteen historian suurkatselmus

Kirjallisuusarvostelu

Inhimillinen pääoma ja koulutuspolitiikka OECD arvioiden valossa

Katsauksessa käsitellään OECD:n ja EU:n piirissä viime vuosina tehtyä työtä koulutuksen taloudellisen analyysin alueella.