Innovatiivisen virtuaaliyhteisön edellytykset

Tutkielmassa tutkittiin innovatiivisen virtuaaliyhteisön toiminnan edellytyksiä. Teoreettinen viitekehys muodostui virtuaaliyhteisöjen, innovatiivisuuden ja luovuuden tarkastelusta. Tutkielman empiirisessä osuudessa käytettiin kvalitatiivista tutkimusotetta. Tutkimusaineisto perustui internetiin tutkimusta varten perustetun innovointiin keskittyneen keskustelufoorumin tuottamiin tuloksiin sekä ko. foorumin käyttäjien palautteeseen. Tutkimuksessa kävi ilmi, että innovatiivisuus vaatii motivoitumista käsiteltävään aiheeseen. Ideoijan täytyy kokea aihe mielenkiintoiseksi, jotta virtuaaliyhteisössä tapahtuva innovointi pystyy tarjoamaan parhaan etunsa eli välineen ajasta ja paikasta riippumattomaan ideointiin. Virtuaaliyhteisöllä tulee olla koordinaattori, joka pitää huolen tiedon kokoamisesta, yhteenvedoista ja ruokkii yhteisön aktiivisuutta. Yhteisössä innovoiminen edellyttää yhteisön ilmapiirin rakentamista otolliseksi avoimelle viestinnälle. Tämä syntyy rakentamalla luottamusta toimijoiden välille mm. kannustamalla sosiaaliseen viestintään. Virtuaaliyhteisössä passivoituminen on suuri uhka. Virtuaaliyhteisöä täytyy johtaa kannustaen ja pitäen kaikin keinoin huolta jäsenten aktiivisen keskustelun ylläpidosta. Passiivisuus aiheuttaa yleistä passiivisuutta, aktiivisuus nostaa aktiivisuutta. Toimijoiden anonyymius voi olla yhteisön voimavara, mutta tuo sitoutumattomuutta, jolloin mikä tahansa häiritsevä tekijä saa aikaan sen, että toimija voi jättää osallistumatta asian käsittelyyn ilman muualta kohdistuvia paineita. Anonyymiyden hyödyt ja haitat tulee punnita tarkoin.

Fiber-reinforced Composite as Oral Implant Material. Experimental studies of glass fiber and bioactive glass in vitro and in vivo

Fiber-reinforced composite as oral implant material: Experimental studies of glass fiber and bioactive glass in vitro and in vivo Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku, Turku, Finland 2008. Biocompatibility and mechanical properties are important variables that need to be determined when new materials are considered for medical implants. Special emphasis was placed on these characteristics in the present work, which aimed to investigate the potential of fiber-reinforced composite (FRC) material as an oral implant. Furthermore, the purpose of this study was to explore the effect of bioactive glass (BAG) on osseointegration of FRC implants. The biocompatibility and mechanical properties of FRC implants were studied both in vitro and in vivo. The mechanical properties of the bulk FRC implant were tested with a cantilever bending test, torsional test and push-out test. The biocompatibility was first evaluated with osteoblast cells cultured on FRC substrates. Bone bonding was determined with the mechanical push-out test and histological as well as histomorplanimetric evaluation. Implant surface was characterized with SEM and EDS analysis. The results of these studies showed that FRC implants can withstand the static load values comparably to titanium. Threaded FRC implants had significantly higher push-out strength than the threaded titanium implants. Cell culture study revealed no cytotoxic effect of FRC materials on the osteoblast-like-cells. Addition of BAG particles enhanced cell proliferation and mineralization of the FRC substrates The in vivo study showed that FRC implants can withstand static loading until failure without fracture. The results also suggest that the FRC implant is biocompatible in bone. The biological behavior of FRC was comparable to that of titanium after 4 and 12 weeks of implantation. Furthermore, addition of BAG to FRC implant increases peri-implant osteogenesis and bone maturation.

Non-resorbable glass fibre-reinforced composite with porous surface as bone substitute material: Experimental studies in vitro and in vivo focused on bone-implant interface

The development of load-bearing osseous implant with desired mechanical and surface properties in order to promote incorporation with bone and to eliminate risk of bone resorption and implant failure is a very challenging task. Bone formation and resoption processes depend on the mechanical environment. Certain stress/strain conditions are required to promote new bone growth and to prevent bone mass loss. Conventional metallic implants with high stiffness carry most of the load and the surrounding bone becomes virtually unloaded and inactive. Fibre-reinforced composites offer an interesting alternative to metallic implants, because their mechanical properties can be tailored to be equal to those of bone, by the careful selection of matrix polymer, type of fibres, fibre volume fraction, orientation and length. Successful load transfer at bone-implant interface requires proper fixation between the bone and implant. One promising method to promote fixation is to prepare implants with porous surface. Bone ingrowth into porous surface structure stabilises the system and improves clinical success of the implant. The experimental part of this work was focused on polymethyl methacrylate (PMMA) -based composites with dense load-bearing core and porous surface. Three-dimensionally randomly orientated chopped glass fibres were used to reinforce the composite. A method to fabricate those composites was developed by a solvent treatment technique and some characterisations concerning the functionality of the surface structure were made in vitro and in vivo. Scanning electron microscope observations revealed that the pore size and interconnective porous architecture of the surface layer of the fibre-reinforced composite (FRC) could be optimal for bone ingrowth. Microhardness measurements showed that the solvent treatment did not have an effect on the mechanical properties of the load-bearing core. A push-out test, using dental stone as a bone model material, revealed that short glass fibre-reinforced porous surface layer is strong enough to carry load. Unreacted monomers can cause the chemical necrosis of the tissue, but the levels of leachable resisidual monomers were considerably lower than those found in chemically cured fibre-reinforced dentures and in modified acrylic bone cements. Animal experiments proved that surface porous FRC implant can enhance fixation between bone and FRC. New bone ingrowth into the pores was detected and strong interlocking between bone and the implant was achieved.

Hemicellulose extracted Kraft pulp as a raw material of paper

The transformation of a traditional pulp mill into an integrated forest biorefinery utilizing wood-derived biomass presents a promising opportunity for enterprise revival of the pulp and paper industry by offering new sources of revenue and significantly improved industry profitability. One proposed next generation process step for an integrated forest biorefinery is the extraction of hemicelluloses, allowing the co-production of pulp and ethanol or chemicals. The extraction of hemicelluloses, however, will likely have downstream effects on pulp quality. In the literature survey an overview of the integrated forest biorefinery and possible next generation technologies implementable in such facility were reviewed. Moreover, some hemicellulose extraction methods suitable for the co-production of pulp and hemicellulose products were looked into in more detail. Also, an overview on the significance of pulp’s hemicellulose content on papermaking properties of pulp fibers was made. In the literature it is stated that the hemicellulose content of pulp affects on many papermaking properties of pulp fibers, hornification and paper strength properties in particular. In the experimental part the goal was to investigate what effects alkaline hemicellulose extraction after bleaching has on the papermaking properties of birch Kraft pulp. It was discovered that tested pulps, normal and hemi-poor birch Kraft pulp, were different in many ways regarding to pulp properties. Differences were observed in both physical and chemical characteristics. Furthermore, clear distinctions were seen in tested paper properties, especially in strength properties, between the handsheets made from hemi-poor or normal birch Kraft pulp. Hemi-poor and normal birch Kraft pulps were also compared as a raw material of laboratory made copy paper. Based on this comparison, usage of hemi-poor birch pulp as the raw material of copy paper does not drastically deteriorate its quality.

Effects of Silica Based Biomaterials on Bone Marrow Derived Cells - Material Aspects of Bone Regeneration

Silica based biomaterials, such as melt-derived bioactive glasses and sol-gel glasses, have been used for a long time in bone healing applications because of their ability to form hydroxyapatite and to stimulate stem cell proliferation and differentiation. In this study, bone marrow derived cells were cultured with bioactive glass and sol-gel silica, and seeded into porous polymer composite scaffolds that were then implanted femorally and subcutaneously in rats to monitor their migration inside host tissue. Bone marrow derived cells were also injected intraperitoneally. Transplanted cells migrated to various tissues inside the host, including the lung, liver spleen, thymus and bone marrow. The method of transplantation affected the time frame of cell migration, with intraperitoneal injection being the fastest and femoral implantation the slowest, but not the target tissues of migration. Transplanted donor cells had a limited lifetime in the host and were later eliminated from all tested tissues. Bioactive glass, however, affected the implanted cells negatively. When it was present in the scaffold no donor cells were found in any of the tested host tissues. Bioactive glass S53P4 was found to support both osteoblastic and osteoclastic phenotype of bone marrow derived cells, but it was resistant to the resorbing effect of osteoclastic bone marrow derived cells, showing that bioactive glass is rather dissolved through physicochemical reactions than resorbed by cells. Fast-dissolving silica sol gel in microparticulate form was found to increase collagen formation by bone marrow derived cells, while slow dissolving silica microparticles enhanced their proliferation, suggesting that the dissolution rate of silica controls the response of bone marrow derived cells.

Economics of combined power plant and pyrolysis bio-oil production

There are reasons of necessity in bio-fuel use and bio-energy fast development. It includes the material about bio-energy technologies, applications and methods. There are basic thermodynamics and economic theories. The economic calculation presents the comparison between two combinations. There are boiler plant below 20 MW in combination with ablative pyrolysis plant for bio-oil production and CHP plant below 100 MW in combination with the RTP pyrolysis bio-oil production technology. It provides a material about wood chips and bio-oil characteristics and explains it nature, presents the situation around the bio-fuel market or bio-fuel trade. There is a description of pyrolysis technologies such as ablative and RTP. The liquid product of the pyrolysis processes is bio-oil. The bio-oil could be different even of the same production process, because of the raw material nature and characteristics. The calculation shows advantages and weaknesses of combinations and obtained a proof of suppositions. The next thing, proven by this work is the fact that to get more efficiency from energy project it is good possibility to built plants in combinations.

Hvordan øve hellige handlinger? : en profesjonsdidaktisk studie av øving av muntlige ferdigheter innenfor en norsk presteutdanning

How can the holy craft of liturgy be trained? A study of approaches to instruction in training oral skills within education of the Norwegian clergy The theme of this study is the competence of expression of clerics performing liturgies as part of their duties in the Norwegian Lutheran Church. The aim of the study is to find a teaching practice which can raise the competence in oral expression characteristic of the clergy profession. The teaching practice is explored and discussed within the context of the basic education of the clergy. The main thesis is formulated as a question: How can the holy craft of liturgy be trained? An underpinning of the study is that liturgical acts are holy, which gives these performances an aspect of otherness. This otherness constitutes a clear agreement between the students and the teacher, and between the professional and the employer. The pre-understanding of the researcher is that these liturgical oral acts are trainable, and that there is a need and a necessity to train in these skills. Three research questions are elaborated on in the explorative section of the study: • What is characteristic of a competence of expression connected to the profession? • How can this competence of expression connected to liturgical performance be developed? • What is the importance of this competence in the holy craft of liturgy for the development of a cohesive professional self-understanding? The study is based on a research and development project where the researcher as the teacher and students from one specific clergy education in Norway (MF) were the source of the empirical material. The empirical data came from practice with two external observers› logs on the coaching, video observations, of the teacher and the students› texts on the practice under study, which is liturgical performance. The researcher›s log and field notes also provide material for the analysis. This is a qualitative project and an arts education project carried out within an interpretative framework. The theoretical framework has three perspectives: a structural approach based on the system theory of Niklas Luhmann, an epistemological approach discussing forms of knowledge in practice or informing practice and an arts education approach. The results indicate that the competence in oral liturgical performance can be considered a trainable skill, and that this training can be understood as an arts education method of instruction based on meaningful communication, dramaturgical thinking and the development of authenticity. The main result from this study can be considered as articulating and sketching the contours of the field of knowledge where the students embody the meaning of the clergy profession ‒ and this articulation has an innovative potential as knowledge combining experience and theoretical understanding.

Wood as a model material for medical biomaterials. In vivo and in vitro studies with bone and Betula pubescens Ehrh

Novel biomaterials are needed to fill the demand of tailored bone substitutes required by an ever‐expanding array of surgical procedures and techniques. Wood, a natural fiber composite, modified with heat treatment to alter its composition, may provide a novel approach to the further development of hierarchically structured biomaterials. The suitability of wood as a model biomaterial as well as the effects of heat treatment on the osteoconductivity of wood was studied by placing untreated and heat‐treated (at 220 C , 200 degrees and 140 degrees for 2 h) birch implants (size 4 x 7mm) into drill cavities in the distal femur of rabbits. The follow‐up period was 4, 8 and 20 weeks in all in vivo experiments. The flexural properties of wood as well as dimensional changes and hydroxyl apatite formation on the surface of wood (untreated, 140 degrees C and 200 degrees C heat‐treated wood) were tested using 3‐point bending and compression tests and immersion in simulated body fluid. The effect of premeasurement grinding and the effect of heat treatment on the surface roughness and contour of wood were tested with contact stylus and non‐contact profilometry. The effects of heat treatment of wood on its interactions with biological fluids was assessed using two different test media and real human blood in liquid penetration tests. The results of the in vivo experiments showed implanted wood to be well tolerated, with no implants rejected due to foreign body reactions. Heat treatment had significant effects on the biocompatibility of wood, allowing host bone to grow into tight contact with the implant, with occasional bone ingrowth into the channels of the wood implant. The results of the liquid immersion experiments showed hydroxyl apatite formation only in the most extensively heat‐treated wood specimens, which supported the results of the in vivo experiments. Parallel conclusions could be drawn based on the results of the liquid penetration test where human blood had the most favorable interaction with the most extensively heat‐treated wood of the compared materials (untreated, 140 degrees C and 200 degrees C heat‐treated wood). The increasing biocompatibility was inferred to result mainly from changes in the chemical composition of wood induced by the heat treatment, namely the altered arrangement and concentrations of functional chemical groups. However, the influence of microscopic changes in the cell walls, surface roughness and contour cannot be totally excluded. The heat treatment was hypothesized to produce a functional change in the liquid distribution within wood, which could have biological relevance. It was concluded that the highly evolved hierarchical anatomy of wood could yield information for the future development of bulk bone substitutes according to the ideology of bioinspiration. Furthermore, the results of the biomechanical tests established that heat treatment alters various biologically relevant mechanical properties of wood, thus expanding the possibilities of wood as a model material, which could include e.g. scaffold applications, bulk bone applications and serving as a tool for both mechanical testing and for further development of synthetic fiber reinforced composites.

Spectrometrical Monitoring of Laser Sintering Process of Ceramic Material

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.

Generation and Characterization of Knockout Mice and Analysis of Patient Material Demonstrates a Role for Tissue Inhibitor of Metalloproteinases 4 (Timp4) in the Cardiovascular System and Tumor Metastasis

This thesis focuses on tissue inhibitor of metalloproteinases 4 (TIMP4) which is the newest member of a small gene and protein family of four closely related endogenous inhibitors of extracellular matrix (ECM) degrading enzymes. Existing data on TIMP4 suggested that it exhibits a more restricted expression pattern than the other TIMPs with high expression levels in heart, brain, ovary and skeletal muscle. These observations and the fact that the ECM is of special importance to provide the cardiovascular system with structural strength combined with elasticity and distensibility, prompted the present molecular biologic investigation on TIMP4. In the first part of the study the murine Timp4 gene was cloned and characterized in detail. The structure of murine Timp4 genomic locus resembles that in other species and of the other Timps. The highest Timp4 expression was detected in heart, ovary and brain. As the expression pattern of Timp4 gives only limited information about its role in physiology and pathology, Timp4 knockout mice were generated next. The analysis of Timp4 knockout mice revealed that Timp4 deficiency has no obvious effect on the development, growth or fertility of mice. Therefore, Timp4 deficient mice were challenged using available cardiovascular models, i.e. experimental cardiac pressure overload and myocardial infarction. In the former model, Timp4 deficiency was found to be compensated by Timp2 overexpression, whereas in the myocardial infarct model, Timp4 deficiency resulted in increased mortality due to increased susceptibility for cardiac rupture. In the wound healing model, Timp4 deficiency was shown to result in transient retardation of re-epithelialization of cutaneous wounds. Melanoma tumor growth was similar in Timp4 deficient and control mice. Despite of this, lung metastasis of melanoma cells was significantly increased in Timp4 null mice. In an attempt to translate the current findings to patient material, TIMP4 expression was studied in human specimens representing different inflammatory cardiovascular pathologies, i.e. giant cell arteritis, atherosclerotic coronary arteries and heart allografts exhibiting signs of chronic rejection. The results showed that cardiovascular expression of TIMP4 is elevated particularly in areas exhibiting inflammation. The results of the present studies suggest that TIMP4 has a special role in the regulation of tissue repair processes in the heart, and also in healing wounds and metastases. Furthermore, evidence is provided suggesting the usefulness of TIMP4 as a novel systemic marker for vascular inflammation.

Suomen Ilmavoimien johtamisjärjestelmän evoluutio ilmasotateorian, kansallisten instituutioiden ja johtamisjärjestelmän ulkomaisen kehityksen näkökulmasta

Ilmavoimien johtamisjärjestelmä on osa Ilmavoimien järjestelmäkokonaisuutta, jonka kaksi muuta osaa ovat taistelujärjestelmä ja tukeutumisjärjestelmä. Ilmavoimien materiaalista suorituskykyä rakennetaan tämän järjestelmäajattelun pohjalta. tässä tutkimuksessa Ilmavoimien johtamisjärjestelmää tutkitaan kolmen kokonaisuuden, ilmavalvontajärjestelmän, ilmatilannekuvan muodostamisjärjestelmän ja tulenkäytön johtamisjärjestelmän, näkökulmasta. Ilmavoimien johtamisjärjestelmän laajuuden vuoksi tutkimusaluetta on jouduttu rajaamaan. Tutkimus perustuu evoluutioparadigmaan, jonka mukaisesti kaikki olevainen on evolutionaarista. Mikään tässä ajassa oleva ilmiö ei ole historiaton. Jokaisella ilmiöllä on nykyisyytensä lisäksi historia ja tulevaisuus. Evoluutioparadigman avulla laajennetaan Ilmavoimien johtamisjärjestelmän nykyisyyden ymmärtämistä kuvaamalla ja analysoimalla sen evoluutiota. Tutkimusaineistoa analysoidaan käyttäen hyväksi polkuriippuvuutta evolutionaarisena mallina. tätä mallia on käytetty uusinstitutionaalisessa ja evolutionaarisessa taloustieteessä ja taloushistoriassa tutkittaessa yritysten, toimialojen tai tuotteiden pysyvyyttä markkinoilla sekä erilaisten innovaatioiden vaikuttavuutta menestymiseen eri markkinatilanteissa. Tutkimusasetelman lähtökohtana on Ilmavoimien johtamisjärjestelmäevoluution kuvaaminen kolmen tekijän tasapainoasetelman suhteen, joita ovat instituutiot, ilmasotateoria ja kansainvälinen ilmavoimien johtamisjärjestelmän kehitys. tutkimuksen tavoitteena on löytää institutionaalinen logiikka Ilmavoimien johtamisjärjestelmän evoluutiolle sekä sen eri kehitysprosesseihin liittyvä mahdollinen polkuriippuvuuden logiikka. Tutkittavina instituutioina ovat kansallinen poliittinen päätöksenteko, joka ilmentyy erilaisina komiteamietintöjä, raportteina ja selontekoina. Sotilaallista instituutiota edustavat eri operatiiviset ohjeet, ohjesäännöt ja doktriinit, jotka ovat ohjanneet johtamisjärjestelmäkehitystä. Ilmasotateorian vaikuttavuuden analyysiä varten tutkimuskohteiksi on valittu seitsemän merkittävää ilmasotateoreetikkoa. Kenraalimajuri Giulio douhet, ilmamarsalkka Hugh Trenchard ja kenraalimajuri William Mitchell edustavat ilmasotateorian varhaista kautta. Kansallista ilmasotateorian kehitystä edustavat eversti Richard Lorentz ja kenraalimajuri Gustaf Erik Magnusson. Yhdysvaltalaiset everstit John Boyd ja John Warden III ovat uuden ajan ilmasotateoreetikkoja. Näiden henkilöiden tuottamien teorioiden avulla voidaan piirtää kuva muutoksesta, jota ilmasodankäynnin teoreetti- sessa ajattelussa on tapahtunut. Ilmavoimien johtamisjärjestelmän evoluutiolle haetaan vertailua kehityksestä, jota on tapahtunut Yhdysvalloissa, Isossa-Britanniassa ja Saksassa. Ilmavoimat on saanut vaikutteita muistakin maista, mutta näiden maiden kehityksen avulla voidaan selittää Suomessa tapahtunutta kehitystä. Tutkimuksessa osoitetaan, että kansainvälisellä johtamisjärjestelmäevoluutiolla on ollut merkittävä vaikutus suomalaiseen kehitykseen. Tämä tutkimus laajentaa prosessuaalista tutkimusteoriaa ja polkuriippuvuusmallin käyttöä sotatieteelliseen tutkimuskenttään. tutkimus yhdistää toisiinsa aivan uudella tavalla sotilasorganisaation institutionaalisia tekijöitä pitkässä evoluutioketjussa. Tutkimus luo pohjaa prosessuaaliseen, havaintoihin perustuvaan evoluutioajatteluun, jossa eri tekijöiden selitysmalleja ja kausaalisuutta eri periodien aikana voidaan kuvata. Tutkimuksen tuloksena ilmavoimien johtamisjärjestelmäevoluutiossa paljastui merkittäviä piirteitä. Teknologia on ollut voimakas katalysaattori ilmapuolustuksen evoluutiossa. Uusien teknologisten innovaatioiden ilmestyminen taistelukentälle on muuttanut oleellisesti taistelun kuvaa. Sodankäynnin revoluutiosta huolimatta sodankäynnin tai operaatiotaidon ja taktiikan perusperiaatteissa ei ole tapahtunut perustavanlaatuista muutosta. Ilmavoimien johtamisjärjestelmän kehitys on voimakkaasti linkittynyt ulkomaiseen johtamisjärjestelmäkehitykseen, jossa teknologiaimplementaatiot perustuvat usean eri ilmiön paljastumiseen ja hyväksikäyttöön. Sotilas- ja siviili-instituutiot ovat merkittävästi vaikuttaneet Ilmavoimien johtamisjärjestelmän kansalliseen kehitykseen. Ne ovat antaneet poliittisen ohjauksen, taloudellisten resurssien ja strategis-operatiivisten käskyjen ja suunnitelmien avulla perusteet, joiden pohjalta johtamisjärjestelmää on kehitetty. Tutkimus osoittaa, että Suomen taloudellisten resurssien rajallisuus on ollut merkittävin institutionaalinen rajoite Ilmavoimien johtamisjärjestelmää kehitettäessä. Useat poliittiset ohjausasiakirjat ovat korostaneet, ettei Suomella pienenä kansakuntana ole taloudellisia resursseja seurata kansainvälistä sotilasteknologiakehitystä. Lisäksi ulko- ja turvallisuuspoliittinen liikkumavapaus on vaikuttanut kehittämismahdollisuuksiin. Ilmasotateorian evoluutio on luonut johtamisjärjestelmän kehitykselle välttämättömän konseptuaalisen viitekehyksen, jotta ilmasota on voitu viedä käytännön tasolle. Teoria, doktriini ja instituutiot toimivat vuorovaikutuksessa, jossa ne interaktiivisesti vaikuttavat toinen toisiinsa. Tutkimus paljasti kuusi merkittävää sokkia, jotka saivat aikaan radikaaleja muutoksia johtamisjärjestelmän evoluutiopolulla. tutkimuksen perusteella vaikuttavimmat muutoksia aiheuttavat sokit olivat radikaalit turvallisuuspoliittiset muutokset kuten sota ja voimakkaat kansantalouden muutokset kuten lama. Sokkeja aiheuttaneet kuusi ajankohtaa olivat: 1. Puolustusvoimien rakentamisen aloittaminen vapaussodan jälkeen 1918 2. Maailmanlaajuinen lama 1929–1933 ja eurooppalainen rauhanaate 1928–1933 3. Talvi- ja jatkosota 1939–1944 4. Uusi alku Pariisin rauhansopimuksen 1947 ja YYA-sopimuksen 1948 varjossa 5. Kylmän sodan päättyminen ja Suomen lama 1990–1993 6. Maailmanlaajuinen lama 2008- Tutkimuksen perusteella voidaan todeta, että Suomen ilmavoimien johtamisjärjestelmän kehittäminen on perustunut rationaalisiin päätöksiin, jotka ovat saaneet vaikutteita ulkomaisesta ilmasotateorian ja -doktriinien kehityksestä sekä kansainvälisestä johtamisjärjestelmäkehityksestä. Johtamisjärjestelmän evoluutioon on vaikuttanut globaali konvergenssi, johon on tehty kansallisen tason ratkaisuja järjestelmien adaptaation ja implementaation yhteydessä.

Repair of segmental bone defects with fiber-reinforced composite: a study of material development and an animal model on rabbits

The Repair of segmental defects in load-bearing long bones is a challenging task because of the diversity of the load affecting the area; axial, bending, shearing and torsional forces all come together to test the stability/integrity of the bone. The natural biomechanical requirements for bone restorative materials include strength to withstand heavy loads, and adaptivity to conform into a biological environment without disturbing or damaging it. Fiber-reinforced composite (FRC) materials have shown promise, as metals and ceramics have been too rigid, and polymers alone are lacking in strength which is needed for restoration. The versatility of the fiber-reinforced composites also allows tailoring of the composite to meet the multitude of bone properties in the skeleton. The attachment and incorporation of a bone substitute to bone has been advanced by different surface modification methods. Most often this is achieved by the creation of surface texture, which allows bone growth, onto the substitute, creating a mechanical interlocking. Another method is to alter the chemical properties of the surface to create bonding with the bone – for example with a hydroxyapatite (HA) or a bioactive glass (BG) coating. A novel fiber-reinforced composite implant material with a porous surface was developed for bone substitution purposes in load-bearing applications. The material’s biomechanical properties were tailored with unidirectional fiber reinforcement to match the strength of cortical bone. To advance bone growth onto the material, an optimal surface porosity was created by a dissolution process, and an addition of bioactive glass to the material was explored. The effects of dissolution and orientation of the fiber reinforcement were also evaluated for bone-bonding purposes. The Biological response to the implant material was evaluated in a cell culture study to assure the safety of the materials combined. To test the material’s properties in a clinical setting, an animal model was used. A critical-size bone defect in a rabbit’s tibia was used to test the material in a load-bearing application, with short- and long-term follow-up, and a histological evaluation of the incorporation to the host bone. The biomechanical results of the study showed that the material is durable and the tailoring of the properties can be reproduced reliably. The Biological response - ex vivo - to the created surface structure favours the attachment and growth of bone cells, with the additional benefit of bioactive glass appearing on the surface. No toxic reactions to possible agents leaching from the material could be detected in the cell culture study when compared to a nontoxic control material. The mechanical interlocking was enhanced - as expected - with the porosity, whereas the reinforcing fibers protruding from the surface of the implant gave additional strength when tested in a bone-bonding model. Animal experiments verified that the material is capable of withstanding load-bearing conditions in prolonged use without breaking of the material or creating stress shielding effects to the host bone. A Histological examination verified the enhanced incorporation to host bone with an abundance of bone growth onto and over the material. This was achieved with minimal tissue reactions to a foreign body. An FRC implant with surface porosity displays potential in the field of reconstructive surgery, especially regarding large bone defects with high demands on strength and shape retention in load-bearing areas or flat bones such as facial / cranial bones. The benefits of modifying the strength of the material and adjusting the surface properties with fiber reinforcement and bone-bonding additives to meet the requirements of different bone qualities are still to be fully discovered.

Summaries of lecture recordings used as learning material in blended learning

Julkaisumaa: 530 AN ANT Alankomaiden Antillit