Summaries of lecture recordings used as learning material in blended learning

Julkaisumaa: 530 AN ANT Alankomaiden Antillit

Characterisation of Laser Beam and Paper Material Interaction

It is known already from 1970´s that laser beam is suitable for processing paper materials. In this thesis, term paper materials mean all wood-fibre based materials, like dried pulp, copy paper, newspaper, cardboard, corrugated board, tissue paper etc. Accordingly, laser processing in this thesis means all laser treatments resulting material removal, like cutting, partial cutting, marking, creasing, perforation etc. that can be used to process paper materials. Laser technology provides many advantages for processing of paper materials: non-contact method, freedom of processing geometry, reliable technology for non-stop production etc. Especially packaging industry is very promising area for laser processing applications. However, there are only few industrial laser processing applications worldwide even in beginning of 2010´s. One reason for small-scale use of lasers in paper material manufacturing is that there is a shortage of published research and scientific articles. Another problem, restraining the use of laser for processing of paper materials, is colouration of paper material i.e. the yellowish and/or greyish colour of cut edge appearing during cutting or after cutting. These are the main reasons for selecting the topic of this thesis to concern characterization of interaction of laser beam and paper materials. This study was carried out in Laboratory of Laser Processing at Lappeenranta University of Technology (Finland). Laser equipment used in this study was TRUMPF TLF 2700 carbon dioxide laser that produces a beam with wavelength of 10.6 μm with power range of 190-2500 W (laser power on work piece). Study of laser beam and paper material interaction was carried out by treating dried kraft pulp (grammage of 67 g m-2) with different laser power levels, focal plane postion settings and interaction times. Interaction between laser beam and dried kraft pulp was detected with different monitoring devices, i.e. spectrometer, pyrometer and active illumination imaging system. This way it was possible to create an input and output parameter diagram and to study the effects of input and output parameters in this thesis. When interaction phenomena are understood also process development can be carried out and even new innovations developed. Fulfilling the lack of information on interaction phenomena can assist in the way of lasers for wider use of technology in paper making and converting industry. It was concluded in this thesis that interaction of laser beam and paper material has two mechanisms that are dependent on focal plane position range. Assumed interaction mechanism B appears in range of average focal plane position of 3.4 mm and 2.4 mm and assumed interaction mechanism A in range of average focal plane position of 0.4 mm and -0.6 mm both in used experimental set up. Focal plane position 1.4 mm represents midzone of these two mechanisms. Holes during laser beam and paper material interaction are formed gradually: first small hole is formed to interaction area in the centre of laser beam cross-section and after that, as function of interaction time, hole expands, until interaction between laser beam and dried kraft pulp is ended. By the image analysis it can be seen that in beginning of laser beam and dried kraft pulp material interaction small holes off very good quality are formed. It is obvious that black colour and heat affected zone appear as function of interaction time. This reveals that there still are different interaction phases within interaction mechanisms A and B. These interaction phases appear as function of time and also as function of peak intensity of laser beam. Limit peak intensity is the value that divides interaction mechanism A and B from one-phase interaction into dual-phase interaction. So all peak intensity values under limit peak intensity belong to MAOM (interaction mechanism A one-phase mode) or to MBOM (interaction mechanism B onephase mode) and values over that belong to MADM (interaction mechanism A dual-phase mode) or to MBDM (interaction mechanism B dual-phase mode). Decomposition process of cellulose is evolution of hydrocarbons when temperature is between 380- 500°C. This means that long cellulose molecule is split into smaller volatile hydrocarbons in this temperature range. As temperature increases, decomposition process of cellulose molecule changes. In range of 700-900°C, cellulose molecule is mainly decomposed into H2 gas; this is why this range is called evolution of hydrogen. Interaction in this range starts (as in range of MAOM and MBOM), when a small good quality hole is formed. This is due to “direct evaporation” of pulp via decomposition process of evolution of hydrogen. And this can be seen can be seen in spectrometer as high intensity peak of yellow light (in range of 588-589 nm) which refers to temperature of ~1750ºC. Pyrometer does not detect this high intensity peak since it is not able to detect physical phase change from solid kraft pulp to gaseous compounds. As interaction time between laser beam and dried kraft pulp continues, hypothesis is that three auto ignition processes occurs. Auto ignition of substance is the lowest temperature in which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. Three auto ignition processes appears in range of MADM and MBDM, namely: 1. temperature of auto ignition of hydrogen atom (H2) is 500ºC, 2. temperature of auto ignition of carbon monoxide molecule (CO) is 609ºC and 3. temperature of auto ignition of carbon atom (C) is 700ºC. These three auto ignition processes leads to formation of plasma plume which has strong emission of radiation in range of visible light. Formation of this plasma plume can be seen as increase of intensity in wavelength range of ~475-652 nm. Pyrometer shows maximum temperature just after this ignition. This plasma plume is assumed to scatter laser beam so that it interacts with larger area of dried kraft pulp than what is actual area of beam cross-section. This assumed scattering reduces also peak intensity. So result shows that assumably scattered light with low peak intensity is interacting with large area of hole edges and due to low peak intensity this interaction happens in low temperature. So interaction between laser beam and dried kraft pulp turns from evolution of hydrogen to evolution of hydrocarbons. This leads to black colour of hole edges.

Punção aspirativa por agulha fina como método de coleta de material para a histopatologia no osteossarcoma canino

Para a obtenção do diagnóstico definitivo do osteossarcoma realizam-se exames citopatológico e histopatológico. O material para exame citopatológico é coletado através de punção aspirativa por agulha fina (PAAF), já para a realização do exame histopatológico é necessário uma amostra de tamanho maior, geralmente conseguida através de biópsia incisional. Este trabalho tem como objetivo desenvolver uma técnica de coleta de material em cães com suspeita de osteossarcoma através de PAAF para a realização de exame histopatológico. Foram coletadas duas amostras de 12 cães suspeitos de osteossarcoma por PAAF. O material obtido pela primeira coleta foi utilizado para confirmar o diagnóstico através do exame citopatológico, enquanto que o material oriundo da segunda coleta foi fixado em formol a 10% para a análise histopatológica. Quatro das 12 amostras (33,3%) avaliadas histopatologicamente pela metodologia proposta obtiveram também o diagnóstico de osteossarcoma. Esses resultados apontam para uma possível adequação da técnica de coleta de material por PAAF para exame histopatológico.

Carbon Nanotubes as Material for Supercapacitor Electrodes

Electrochemical double-layer supercapacitors have an intermediate position between rechargeable batteries, which can store high amounts of energy, and dielectric capacitors, which have high output power. Supercapacitors are widely suggested to be used in automobiles (recuperation during braking, facilitate engine starting, electric stabilization of the system), industry (forklifts, elevators), hybrid off-road machinery and also in consumer electronics. Supercapacitor electrodes require highly porous material. Typically, activated carbon is used. Specific surface area of activated carbon is approximately 1000 m2 per gram. Carbon nanotubes represent one of prospective materials. According to numerous studies this material allows to improve the properties of supercapacitors. The task of this Master‘s Thesis was to test multiwalled carbon nanotubes and become confident with the testing methods.

Value added logistics in supply and demand chain : COSTFIX : New operation model for maintenance material logistics in paper industry

This research report illustrates and examines new operation models for decreasing fixed costs and transforming them into variable costs in the field of paper industry. The report illustrates two cases – a new operation model for material logistics in maintenance and an examination of forklift truck fleet outsourcing solutions. Conventional material logistics in maintenance operation is illustrated and some problems related to conventional operation are identified. A new operation model that solves some of these problems is presented including descriptions of procurement and service contracts and sources of added value. Forklift truck fleet outsourcing solutions are examined by illustrating the responsibilities of a host company and a service provider both before and after outsourcing. The customer buys outsourcing services in order to improve its investment productivity. The mechanism of how these services affect the customer company’s investment productivity is illustrated.

Agility in international fast fashion retailing

The birth of Internet technologies, the developments of fast fashion and multiple retailing channels have created a need for a new, more integrated way for doing retailing. Agility in fast fashion retailing could be seen as a significant way of responding to these changes and furthermore, as a way to respond to consumers’ altering demands. The purpose of this study was to explore the ways in which agile supply chains and integrated multichannel retailing influence the international fast fashion retailing. A framework for agility in retail was developed based on available theoretical considerations in distribution and communication channels. Qualitative research methods and qualitative content analysis were used. Four expert interviews were carried out to gain new perspectives to the objectives. The rest of the data was collected from an industry specific document, expert video and two expert lectures. Following the data collection, the research material was analyzed with qualitative content analysis. The empirical findings on agility in retail were presented based on a coding frame. It was found that agility in retail has multiple parts, which are overlapping and affecting one another. Furthermore, instead of viewing the agile supply chain and integrated multichannel retailing separately of each other as usual, it was found that they should be integrated, and the term “agility” was proposed to denote this approach. Also, it was found that the most common drivers and constrains of integrated multichannel retailing were the new Internet technologies and customer demand. Brick-and-mortar store, online store, mobile devices and social media were found to be the most common retailing channels. Furthermore, in-store technology, click-and-collect approach, NFC-buying, RFID-technology as well as 3D- digital simulations on fabrics and patterns will enhance agility even more in the future. In addition, environmental issues, customer experiences and communication will be important factors. This study has provided new practical insights for the future retailing. Furthermore, it has contributed to the academic research by discussing the traditional approaches of agility in fast fashion retail and bringing in new insights.

Syntyykö Suomeen puulaaksoja - Suomen puutuoteteollisuuden pk-yritysten tila ja tulevaisuus

Metsäteollisuus on tullut Suomeen ulkomaisen pääoman ja tietotaidon avulla vajaat kaksisataa vuotta sitten. Se on toiminut melkein koko jatkosodan jälkeisen ajan suojatussa ympäristössä ja ulkomaisesta kilpailusta riippumattomassa toimintaympäristössä. Kuten Porter ja muut ovat todistaneet, tällainen toimintaympäristö ei kehitä kansainvälisesti kilpailukykyistä teollisuutta globaaleilla markkinoilla. Liittyminen Euroopan unioniin ja sittemmin Euroopan rahaliittoon saattoi puunjalostusteollisuuden täysin uudenlaiseen kilpailutilanteeseen. Sama tapahtui myös alan pk-yrityksille, jotka olivat joutuneet toimimaan heikosti kilpailluilla raaka-ainemarkkinoilla. Tutkimus on tulevaisuudentutkimus, jossa tutkimusongelmia lähestytään kolmen teorian avulla. Porterin klusteriteoria tarjoaa mahdollisuuden arvioida metsäteollisuutta sekä kokonaisuutena että toimivana monimuotoisena organisaationa, jossa kustannukset ja hinta muodostuvat arvoketjun toimijoiden osakustannuksista. Bionomiateoria eli darvinistinen talousteoria testaa suomalaisen puunjalostusteollisuuden pk-yritysten kilpailukykyä ja paineita hakeutua edullisemmille toiminta- alueille. Evoluutioteoria tarkastelee sukupolvenvaihdoksen problematiikkaa. Sukupolvenvaihdoksen onnistuminen muodostuu puutoimialan elämän ja kuoleman kysymykseksi. Tämä on etenkin pk-yrityksiä kohtaava ongelma. Asiaa selvitettiin Mauno Rintalan suorittamalla kyselytutkimuksella Puuteollisuusyrittäjien jäsenistön keskuudessa. Ongelma johtuu suurista sodan jälkeen syntyneistä ikäluokista. Nämä vuosina 1945– 50 syntyneet ovat siirtymässä eläkkeelle vuosien 2005 ja 2015 välillä. Kyseisissä ikäluokissa yritystiheys on noin kaksi kertaa suurempi kuin sen jälkeisissä ikäluokissa. Suoritetun kyselyn sekä muiden suomalaisten ja kansainvälisten tutkimusten perusteella näyttää siltä, että eläkkeelle siirryttäessä vain noin 30 %:lla yrityksistä on jatkaja tiedossa suvusta tai lähipiiristä. Tämä merkitsee sitä, että 70 % eläköityvän ikäluokan omistamista yrityksistä poistuu pysyvästi markkinoilta. Suomessa poistuma merkitsee noin 40 % koko yritysvarannosta eli noin 80 000 yritystä. Tilastot toimivien yritysten määrästä ovat kuitenkin hyvin ristiriitaisia, joten todellista määrää on mahdoton arvioida. Noin suuren määrän poistuminen markkinoilta uhkaa jo hyvinvointivaltion perusrakenteita. Tutkimustulos edellyttää nopeita toimenpiteitä teollisten pkyritysten pelastamiseksi ja säilyttämiseksi Suomessa. Sukupolvenvaihdoksen onnistuminen on tässä prosessissa ensiarvoisessa asemassa. Kaikkien edellä mainittujen yritysten poistuminen markkinoilta edellyttäisi noin 400 000 uuden yrityksen perustamista, koska ainoastaan noin 20 % yrityksistä selviää ensimmäiset kolme vuotta. Tutkimukseen perustuen esitetään prosessimalli sukupolvenvaihdoksen suorittamiseksi. Suomen tärkeimmissä kilpailijamaissa valtioiden metsäomistus on määräävässä asemassa. Meillä metsät ovat yksityisessä omistuksessa ja vain pieni osa valtion omistuksessa. Puumarkkinat toimivat markkinatalouden ehdoilla ilman valtion ohjausta. Ongelmaksi on kehittymässä puun saanti. Metsänomistus on sukupolvien myötä hajaantunut hyvin pieniksi metsälöiksi. Nykyiset metsänomistajat asuvat kaupungeissa ja ovat pääosin palkkatyössä. He eivät ole samalla tavoin riippuvaisia puutuloista kuin heidän esi-isänsä. Metsäverotuksen uudistuminen lisää puun saannin epävarmuutta. Se on muuttumassa pinta-alaverotuksesta puun myynnin verotukseen. Puun myynti on vilkasta ennen järjestelmien vaihtumista ja vähäisempää sen jälkeen. Myös näitä ongelmia on pyritty ratkomaan uudenlaisen metsänomistusmallin avulla. Puuteollisuus on hyvin vanha teollisuudenala. Raaka-aine muodostaa määräävän osan kustannuksista. Muutokset ovat hitaita ja todelliset innovaatiot pitkäkestoisia. Uusia innovaatioita tapahtuu harvoin. Kannattavuutta parannetaan tuoteprosessien ja arvoketjujen kehittämisen kautta. Yhteiskunnan osuus alan kehittämisessä ja säilyttämisessä on ratkaiseva. Asioiden moninaisuus tekee tutkimuksen vaikeaksi, mutta sitäkin tärkeämmäksi kansantalouden kannalta. Tällaisissa suurissa murroksissa korostuu kaikkien päättävien tahojen henkinen valmius ja tahto tehdä oikeita ratkaisuja oikeaan aikaan.

Critical aspects on the behavior of material from the mechanical tool-workpiece interaction in single point diamond turning

Some material aspects such as grain size, purity and anisotropy exert an important influence on surface quality, especially in single point diamond turning. The aim of this paper is to present and discuss some critical factors that can limit the accuracy of ultraprecision machining of non-ferrous metals and to identify the effects of them on the cutting mechanism with single point diamond tools. This will be carried out through observations of machined surfaces and chips produced using optical and scanning electron microscopy. Solutions to reduce the influence of some of these limiting factors related with the mechanism of generation of mirror-like surfaces will be discussed.

Potential benefits of building information modeling for building material supplier

This thesis investigated building information modeling (BIM) from a material supplier’s point of view. The objective was to gain understanding about how a building material supplier could benefit from the growing use of BIM in the AEC (architectural, engineering and construction) industry. Increasing amount of inquiries related to BIM from customers and other interest groups had awoken target company’s interest towards BIM. This thesis acts as a pre-study for the target company related to potential of BIM. First of all BIM and its meaning from a material supplier’s point of view was defined based on a literature review. To reveal the potential benefits of BIM for a material supplier a questionnaire survey and in total of 11 interviews were conducted. Based on the literature review and analyzed results it came clear that BIM offers benefits also for material suppliers. Product libraries and material databases for BIM tools can act as an important marketing channel for material suppliers. Material suppliers could also utilize the information from the BIM models to schedule their deliveries more precisely and potentially even to schedule their own production. All this needs deeper cooperation between material suppliers, contractors and other stakeholders in the AEC industry. Based on the results also first steps for the target company to utilize the growing use of BIM were defined.

Wastewater Treatment and Deinking Sludge Utilization Possibilities for Energy and Material Recovery in the Leningrad Region

Operation of pulp and paper mills generates waste including wastewater treatment sludge and deinking sludge. Both sludge types are generated in large amounts and are mainly disposed of in landfills in the Leningrad Region resulting in environmental degradation. The thesis was aimed at seeking new sustainable ways of sludge utilization. Two paper mills operating in the Leningrad Region and landfilling their sludge were identified: “SCA Hygiene Products Russia” and “Knauf”. The former generates 150 t/day of deinking sludge, the latter – 145 t/day of secondary sludge. Chemical analyses of deinking sludge were performed to assess applicability of sludge in construction materials production processes. Higher heating value on dry basis of both sludge types was determined to evaluate energy potential of sludge generated in the Leningrad Region. Total energy output from sludge incineration was calculated. Deinking sludge could be utilized in the production process of “LSR-Cement” or “Slantsy Cement Plant Cesla” factories, and “Pobeda” and “Nikolsky” brick mills without exceeding current sludge management costs.

Unidirectional fiber-reinforced composite as an oral implant abutment material: Experimental studies of E-glass fiber/BisGMA-TEGDMA polymer in vitro

Fiber-reinforced composites (FRCs) are a new group of non-metallic biomaterials showing a growing popularity in many dental and medical applications. As an oral implant material, FRC is biocompatible in bone tissue environment. Soft tissue integration to FRC polymer material is unclear. This series of in vitro studies aimed at evaluating unidirectional E-glass FRC polymer in terms of mechanical, chemical, and biological properties in an attempt to develop a new non-metallic oral implant abutment alternative. Two different types of substrates were investigated: (a) Plain polymer (BisGMA 50%–TEGDMA 50%) and (b) Unidirectional FRC. The mechanical behavior of high fiber-density FRCs was assessed using a three-point bending test. Surface characterization was performed using scanning electron and spinning disk confocal microscopes. The surface wettability/energy was determined using sessile drop method. The blood response, including blood-clotting ability and platelet morphology was evaluated. Human gingival fibroblast cell responses - adhesion kinetics, adhesion strength, and proliferation activity - were studied in cell culture environment using routine test conditions. A novel tissue culture method was developed and used to evaluate porcine gingival tissue graft attachment and growth on the experimental composite implants. The analysis of the mechanical properties showed that there is a direct proportionality in the relationship between E-glass fiber volume fraction and toughness, modulus of elasticity, and load bearing capacity; however, flexural strength did not show significant improvement when high fiber-density FRC is used. FRCs showed moderate hydrophilic properties owing to the presence of exposed glass fibers on the polymer surface. Blood-clotting time was shorter on FRC substrates than on plain polymer. The FRC substrates also showed higher platelet activation state than plain polymer substrates. Fibroblast cell adhesion strength and proliferation rate were highly pronounced on FRCs. A tissue culture study revealed that gingival epithelium and connective tissue established an immediate close contact with both plain polymer and FRC implants. However, FRC seemed to guide epithelial migration outwards from the tissue/implant interface. Due to the anisotropic and hydrophilic nature of FRC, it can be concluded that this material enhances biological events related with soft tissue integration on oral implant surface.

The role of emotional state, sexual arousal, and alcohol intoxication as situational factors associated with adults’ online sexual contact with children and adolescents

In the present study we explored whether and how the situational factors; emotional states, sexual arousal, and alcohol intoxication influenced the propensity in adults to engage in online sexual contact with children (13 or younger) and adolescents (14 – 17 year olds). The results were compared to a group of adults that had engaged in online sexual contact with adults only (18 or older). We also looked at the variation over time within these situational factors during the online sexual contact with a child, an adolescent, or an adult. The present study was an online self-report survey to the adult populations in Finland, Sweden, and Germany, with a final sample (N = 776) of women and men who were active on the Internet. The participants were asked to report whether, how, and with whom they had engaged in online sexual contact. The results showed that more men than women reported online sexual contact with persons of all age groups, and that the situational factors; emotional states and sexual arousal influenced the propensity in both women and men to engage in online sexual contact with children and adolescents. However, the effects of alcohol intoxication were small and significant only for men. These results indicate that higher levels of emotional state and sexual arousal might increase the propensity to go against social norms and contact children and adolescents online for sexual purposes, but it can also imply that that those who look for online sexual contact online with children and adolescents, are more emotionally and/or sexually aroused than the group that only seek adult company or that these are post-hoc explanations for such sexual activities.

Defining of the material models for stainless steels to be used in FE modeling

The aim of this work is to study the results of tensile tests for austenitic stainless steel type 304 and make accurate FE-models according to the results of the tests. Tensile tests were made at Central Research Institute of Structural Material, Prometey at Saint Petersburg and Mariyenburg in Russia. The test specimens for the tensile tests were produced at Lappeenranta University of Technology in a Laboratory of Steel Structures. In total 4 different tests were made, two with base material specimens and two with transverse butt weld specimens. Each kind of a specimen was tested at room temperature and at low temperature. By comparing the results of room and low temperature tests of similar test specimen we get to study the results of work hardening that affect the austenitic steels at below room temperature. The produced specimens are to be modeled accurately and then imported for nonlinear FEM- analyzing. Using the data gained from the tensile tests the aim is to get the models work like the specimens did during the tests. By using the analyzed results of the FE-models the aim is to calculate and get the stress-strain curves that correspond to the results acquired from the tensile tests.