Design structure matrix ja sen hyödyntäminen ohjelmistotuotannossa

Työn tarkoituksena on selvittää, miten DSM ja siihen liittyvät analyysit toimivat. Työssä selvitetään myös, miten DSM:a voidaan hyödyntää tuotekehityksessä ja ohjelmistotuotannon kohtaamissa ongelmissa. DSM-neliömatriisiin sijoitetaan tarkasteltavan kohteen osat riveihin ja kolumneihin identtisessä järjestyksessä. Matriisin soluihin merkitään osien väliset riippuvuudet, joilla selvitetään kunkin osan lähettämä ja vastaanottama data suhteessa muihin osiin. DSM-analyysissa osien järjestystä muutetaan suoritus- tai toteutusjärjestyksen mukaisesti parhaaseen järjestykseen. Osat ryhmitellään moduuleihin, jolloin esimerkiksi tuotekehitys ohjautuu automaattisesti modulaarisuuteen. Tuotekehitysprojekteihin DSM on kompaktin muodon, yksinkertaisuuden ja automaattisen järjestelyn ansiosta erinomainen työkalu, jolla voidaan mallintaa käytännössä mitä tahansa, mikä voidaan jakaa toisistaan riippuviin osiin. DSM voi vähentää projektien suunnitteluun vaadittua työmäärää ja avustaa realististen budjettien ja aikataulujen luontia suurissa projekteissa.

Magnetization studies of polystyrene/multiwall carbon nanotube composite films

Lappeenranta University of Technology School of Technology Technical Physics Evgenii Zhukov MAGNETIZATION STUDIES OF POLYSTYRENE/MULTIWALL CARBON NANOTUBE COMPOSITE FILMS Master’s thesis 2015 55 pages, 41 pictures, 9 Tables. Examiners: Professor Erkki Lähderanta D.Sc. Ivan Zakharchuk Keywords: polystyrene, multi-walled carbon nanotubes, MWCNT, composite, magnetization, SQUID. In this thesis magnetic properties of polystyrene/multiwall carbon nanotube (MWCNT) composites are investigated with Quantum Design SQUID magnetometer (MPMS XL). The surface of the composite films is studied via BRUKER Multimode 8 Atomic Force Microscope, as well. The polystyrene/MWCNT composites have been prepared by the group of professor Okotrub (Physics Chemistry of Nanomaterials laboratory, Nikolaev Institute of Inorganic Chemistry, Russia). The composite films have been prepared by solution processing and stretching method. The approximate length and inner diameter of the MWCNTs used in fabrication are 260 μm and 10 nm, respectively. The content of MWCNTs is 1 and 2.5 contents percent (wt%) for studied samples. The stretching of the samples is 30% for samples with 1 and 2.5 wt% content, and one sample with 1 wt% loading of MWCNTs is 100% stretched. MWCNTs aligned perpendicular to a silicon substrate are used as a reference sample. The magnetization field dependencies of the samples exhibit hysteresis behavior. The values of saturation magnetization of composite films are much less compared to that of the reference sample. The saturation magnetization coercitivity field value drops with decrease of MWCNT content. At high magnetic fields strong presence of diamagnetism is observed. Measurements in magnetic field parallel and perpendicular to the composite plate display anisotropy with respect to the direction of stretching. Temperature dependences of magnetization for all samples display difference between zero-field cooled and field-cooled curves of magnetization. This divergence confirms the presence of magnetic interactions in the material. The atomic force microscopy study of the composites’ surfaces revealed that they are relatively smooth and the nanotubes are aligned with the axis of stretching to some extent. 

Fiber-reinforced composite fixed dental prostheses: Studies of the materials used as pontics

Fiber-reinforced composite fixed dental prostheses – Studies of the materials used as pontics University of Turku, Faculty of Medicine, Institute of Dentistry, Department of Biomaterials Science, Finnish Doctoral Program in Oral Sciences – FINDOS, Annales Universitatis Turkuensis, Turku, Finland 2015 Fiber-reinforced composites (FRC), a non-metallic biomaterial, represent a suitable alternative in prosthetic dentistry when used as a component of fixed dental prostheses (FDPs). Some drawbacks have been identified in the clinical performance of FRC restorations, such as delamination of the veneering material and fracture of the pontic. Therefore, the current series of studies were performed to investigate the possibilities of enhancing the mechanical and physical properties of FRC FDPs by improving the materials used as pontics, to then heighten their longevity. Four experiments showed the importance of the pontic design and surface treatment in the performance of FRC FDPs. In the first, the load-bearing capacities of inlay-retained FRC FDPs with pontics of various materials and thicknesses were evaluated. Three different pontic materials were assessed with different FRC framework vertical positioning. Thicker pontics showed increased load-bearing capacities, especially ceramic pontics. A second study was completed investigating the influence of the chemical conditioning of the ridge-lap surface of acrylic resin denture teeth on their bonding to a composite resin. Increased shear bond strength demonstrated the positive influence of the pretreatment of the acrylic surfaces, indicating dissolution of the denture surfaces, and suggesting potential penetration of the monomer systems into the surface of denture teeth. A third study analyzed the penetration depth of different monomer systems on the acrylic resin denture teeth surfaces. The possibility of establishing a durable bond between acrylic pontics and FRC frameworks was demonstrated by the ability of monomers to penetrate the surface of acrylic resin denture teeth, measured by a confocal scanning type microscope. A fourth study was designed to evaluate the load-bearing capacities of FRC FDPs using the findings of the previous three studies. In this case, the performance of pre-shaped acrylic resin denture teeth used as pontics with different composite resins as filling materials was evaluated. The filling material influenced the load-bearing capacities, providing more durable FRC FDPs. It can be concluded that the mechanical and physical properties of FRC FDPs can be improved as has been shown in the development of this thesis. The improvements reported then might provide long lasting prosthetic solutions of this kind, positioning them as potentially permanent rehabilitation treatments. Key words: fiber-reinforced composite, fixed dental prostheses, inlay-retained bridges, adhesion, acrylic resin denture teeth, dental material.

Utilization of recycled mineral wool as filler in wood plastic composites

The impact of a recycled mineral wool filler on the various properties of wood plastic composites was studied and the critical factors affecting the formation of the properties were determined. An estimation of the volume of mineral wool fiber waste generated in the European Union between the years 2010-2020 was presented. Furthermore, the effect of fiber pre-treatment on the properties of the wood plastic composites were studied, and the environmental performance of a wood plastic composite containing recycled mineral fibers was assessed. The results showed that the volumes of construction and demolition waste and new mineral wool produced in the European Union are growing annually, and therefore also the volumes of recycled mineral wool waste generated are increasing. The study showed that the addition of recycled mineral wool into composites can enhance some of the mechanical properties and increase the moisture resistance properties of the composites notably. Recycled mineral wool as a filler in wood plastic composites can also improve the fire resistance properties of composites, but it does not protect the polymer matrix from pyrolysis. Fiber pre-treatment with silane solution improved some of the mechanical properties, but generally the use of maleated polypropylene as the coupling agent led to better mechanical and moisture resistance properties. The environmental performance of recycled mineral wool as the filler in wood plastic composites was superior compared to glass fibers. According to the findings, recycled mineral wool fibers can provide a technically and environmentally viable alternative to the traditional inorganic filler materials used in wood plastic composites.