Stability Evaluation of a Paper Machine Wet End

Työssä analysoidaanprosessin vaikutusta paperikoneen stabiiliuteen. Kaksi modernia sanomalehtipaperikonetta analysoitiin ja sen perusteella molemmista prosesseista rakennettiin fysiikan lakeihin perustuvat simulointimallit APROS Paper simulointiohjelmistolla. Työn tavoitteena on selvittää, miten kyseisten koneiden prosessit eroavat toisistaan ja arvioida, miten havaitut erot vaikuttavat prosessien stabiiliuteen. Työssä tarkastellaan periodisten häiriöiden vaimenemista prosessissa. Simuloinnissa herätteenä käytettiin puhdasta valkoista kohinaa, jonka avulla eri taajuistenperiodisten häiriöiden vaimenemista analysoitiin. Prosessien häiriövasteet esitetään taajuuskoordinaatistossa. Suurimmat erot prosessien välillä löytyivät viirakaivosta ja sen sekoitusdynamiikasta. Perinteisen viirakaivon todettiin muistuttavan käyttäytymiseltään sarjaan kytkettyjä ideaalisekoittimia, kun taas pienempitilavuuksisen fluumin todettiin käyttäytyvän lähes kuin putkiviive. Vaikka erotprosessitilavuudessa sekä viirakaivon sekoitusdynamiikassa olivat hyvin selkeät, havaittiin vain marginaalinen ero prosessin välillä periodisten häiriöiden vaimenemisessa, koska erot viiraretentiotasoissa vaikuttivat eniten simulointituloksia. Matalammalla viiraretentiolla operoivan paperikoneen todettiin vaimentavan tehokkaammin prosessihäiriöitä. Samalla retentiotasolla pienempitilavuuksisen prosessin todettiin vaimentavan hitaita prosessihäiriöitä marginaalisesti paremmin. Tutkituista paperikoneista toisella simuloitiin viiraosan vedenpoistomuutoksenvaikutusta viiraretentioon ja paperin koostumukseen. Lisäksi arvioitiin viiraretention säädön toimivuutta. Viiraosan listakengän vedenpoiston todettiin aiheuttavan merkittäviä sakeus- ja retentiohäiriöitä, mikäli sen avulla poistettavan kiintoaineen virtaus tuplaantuisi. Viiraretention säädön todettiin estävän häiriöiden kierron prosessissa, mutta siirtävän ne suoraan rainaan. Retention säädön eikuitenkaan todettu olevan suoranainen häiriön lähde.

Wireless Applications Evaluation and Development Process: Case -Paper Industry Logistics

Sähköisen liiketoiminnan ja mobiliteetin konvergenssi yhdessä teknologisen innovaation kiihtyvän vauhdin kanssa ovat saaneet aikaan kiinnostusta langattomia liiketoimintaratkaisuja kohtaan. Tämän diplomityön tavoitteena oli tutkia sähköisen liiketoiminnan langattomien sovellusten arviointi- ja kehitysprosessia. Työ keskittyy tarkastelemaan paperiteollisuuden toimitusketjun langatonta seurantaa. Tutkimuksessa esitetään langattoman sähköisen liiketoiminnan määritelmä, kuvaillaan langattomuuden eri sovellusalueita ja sovellusten arviointi- ja kehitysprosessin strategisia sekä teknologisia ulottuvuuksia. Työ luo viitekehyksen, jonka avulla tarkastella langattomien teknologioiden merkitystä logistiikassa. Tutkimuksen merkittävin tulos on prosessimalli sovellusten arvioimiseksi ja kehittämiseksi. Mallilla kehitetty langaton sovellus osoittautui tarkastelussa hyödylliseksi toimitusketjun hallinnassa.

Effects of Country of Origin on Consumer Product Evaluations: Finnish clothing products in the minds of Russian tourists

Companies operating in today’s highly internationalized markets consider product differentiation the key priority in pursue to attain a constant competitive advantage in challenging global environment (Baker and Ballington 2002, 158). The main driver affecting companies’ differentiation actions was described as early as 1912 by one of the marketing pioneers A. W. Shaw (1912, 710) as meeting human wants more accurate than the competition, and thus increasing customers’ perceived value and satisfaction. Dickson and Ginter (1987, 2) point out in their study based on earlier research by Chamberlin (1965) and Porter (1976) that differentiation can be based on either tangible characteristics of a product such as design or intangible characteristics such as a brand name and country of origin (hereafter referred to as COO). The concept of COO and its impact on consumers’ evaluation of a product as an extrinsic product cue has been one of the most noteworthy topics in international marketing, having been voluminously examined by over 780 authors in more than 750 academic publications in the past 40 years (Papadopoulos and Heslop 2002, 294). Many of these studies accentuate the significant effect the COO has on consumers’ product attribute evaluations. People routinely associate country images with products and services in order to judge and categorize them based on perceived quality and risk levels; thereby COO can influence the likelihood of a purchase (Peterson and Jolibert 1995, 883-884; Verlegh and Steenkamp 1999, 523). Based on the vast research related to COO in the field of international business, it is widely recognized that the country associated with a product can act in a similar way as the name of a brand and even become a part of product’s total image. Thereby depending on customer’s values and perceptions, the product-country image can either increase or decrease perceived value.

Evaluation of an e-learning course: coercion practices in psychiatric nursing

The goal of the study was to evaluate an e-learning course entitled “Nursing interventions to manage distressed and disturbed patients” and intended for psychiatric nurses, using Kirkpatrick’s evaluation model. The aim was to describe nurses’ reactions, learning, behaviour change and impacts resulting from this e-learning course. This dissertation comprises four papers, and the data were collected 2008-2012 from three different sources; electronic databases, an e-learning platform and psychiatric hospitals. First, a systematic literature review was conducted to understand the effectiveness of e-learning. Second, an RCT study was implemented to investigate the impact of the e-learning course on nurses’ job-satisfaction, knowledge and attitudes (N=158). Third, to complete the picture of nurses views of the e-learning course related to knowledge transfer, the nurses’ perspective was studied (N=33). Lastly, the effects of the e-learning course from nursing managers’ perspective in psychiatric hospital organisations were studied (N=28). The systematic review showed that although the nurses were satisfied with the e-learning, no effects were found in the RCT study of nurses’ job satisfaction. The RCT study showed no effects on nurses’ learning related to knowledge increase, but there was change in attitudes. The managers described the changes in the nurses’ knowledge and attitudes. Among the nurses behaviour changed with knowledge transfer from the e-learning course to practice and they pointed out development issues related to their work. The final impacts of the e-learning course revealed advantages and disadvantages of the e-learning course and its implications for nurses’ work. This dissertation provides new insight into nurses’ reactions, learning, behaviour change and impacts resulting from an e-learning course in their continuing education. In order to improve nurses’ continuing education systematic evaluation is needed, for which Kirkpatrick’s evaluation model is a useful tool.

Effects of Fin Parameters on Gas-Side Heat Transfer Performance of H-Type Finned Tube Bundle in a Waste Heat Recovery Boiler

Alfa Laval Aalborg Oy designs and manufactures waste heat recovery systems utilizing extended surfaces. The waste heat recovery boiler considered in this thesis is a water-tube boiler where exhaust gas is used as the convective heat transfer medium and water or steam flowing inside the tubes is subject to cross-flow. This thesis aims to contribute to the design of waste heat recovery boiler unit by developing a numerical model of the H-type finned tube bundle currently used by Alfa Laval Aalborg Oy to evaluate the gas-side heat transfer performance. The main objective is to identify weaknesses and potential areas of development in the current H-type finned tube design. In addition, numerical simulations for a total of 15 cases with varying geometric parameters are conducted to investigate the heat transfer and pressure drop performance dependent on H-type fin geometry. The investigated geometric parameters include fin width and height, fin spacing, and fin thickness. Comparison between single and double tube type configuration is also conducted. Based on the simulation results, the local heat transfer and flow behaviour of the H-type finned tube is presented including boundary layer development between the fins, the formation of recirculation zone behind the tubes, and the local variations of flow velocity and temperature within the tube bundle and on the fin surface. Moreover, an evaluation of the effects of various fin parameters on heat transfer and pressure drop performance of H-type finned tube bundle has been provided. It was concluded that from the studied parameters fin spacing and fin width had the most significant effect on tube bundle performance and the effect of fin thickness was the least important. Furthermore, the results suggested that the heat transfer performance would increase due to enhanced turbulence if the current double tube configuration is replaced with single tube configuration, but further investigation and experimental measurements are required in order to validate the results.