Production of fungal volatile organic compounds in bedding materials

Selostus: Haihtuvien orgaanisten yhdisteiden muodostuminen kuivikkeissa

Reactivity of silicate liming materials from Northern Europe assessed by Soil Incubation and two pH Stat methods

Selostus: Pohjois-Euroopan silikaattisten kalkitusaineiden reaktiivisuus astiakoemenetelm��ll�� ja kahdella pH-staattisella menetelm��ll�� arvioituna

Theoretical Analysis and Simulations of Vertically Vibrated Granular Materials

The dynamical properties ofshaken granular materials are important in many industrial applications where the shaking is used to mix, segregate and transport them. In this work asystematic, large scale simulation study has been performed to investigate the rheology of dense granular media, in the presence of gas, in a three dimensional vertical cylinder filled with glass balls. The base wall of the cylinder is subjected to sinusoidal oscillation in the vertical direction. The viscoelastic behavior of glass balls during a collision, have been studied experimentally using a modified Newton's Cradle device. By analyzing the results of the measurements, using numerical model based on finite element method, the viscous damping coefficient was determinedfor the glass balls. To obtain detailed information about the interparticle interactions in a shaker, a simplified model for collision between particles of a granular material was proposed. In order to simulate the flow of surrounding gas, a formulation of the equations for fluid flow in a porous medium including particle forces was proposed. These equations are solved with Large Eddy Simulation (LES) technique using a subgrid-model originally proposed for compressible turbulent flows. For a pentagonal prism-shaped container under vertical vibrations, the results show that oscillon type structures were formed. Oscillons are highly localized particle-like excitations of the granular layer. This self-sustaining state was named by analogy with its closest large-scale analogy, the soliton, which was first documented by J.S. Russell in 1834. The results which has been reportedbyBordbar and Zamankhan(2005b)also show that slightly revised fluctuation-dissipation theorem might apply to shaken sand, which appears to be asystem far from equilibrium and could exhibit strong spatial and temporal variations in quantities such as density and local particle velocity. In this light, hydrodynamic type continuum equations were presented for describing the deformation and flow of dense gas-particle mixtures. The constitutive equation used for the stress tensor provides an effective viscosity with a liquid-like character at low shear rates and a gaseous-like behavior at high shear rates. The numerical solutions were obtained for the aforementioned hydrodynamic equations for predicting the flow dynamics ofdense mixture of gas and particles in vertical cylindrical containers. For a heptagonal prism shaped container under vertical vibrations, the model results were found to predict bubbling behavior analogous to those observed experimentally. This bubbling behavior may be explained by the unusual gas pressure distribution found in the bed. In addition, oscillon type structures were found to be formed using a vertically vibrated, pentagonal prism shaped container in agreement with computer simulation results. These observations suggest that the pressure distribution plays a key rolein deformation and flow of dense mixtures of gas and particles under vertical vibrations. The present models provide greater insight toward the explanation of poorly understood hydrodynamic phenomena in the field of granular flows and dense gas-particle mixtures. The models can be generalized to investigate the granular material-container wall interactions which would be an issue of high interests in the industrial applications. By following this approach ideal processing conditions and powder transport can be created in industrial systems.

Logistic Solutions of Imported Renovation Materials

T��m��n diplomity��n tavoitteena oli tutkia saneeraus- ja remontoimistuotteiden osalta maahantuontia Suomeen ja transitoliikennett�� Suomen kautta Ven��j��lle. L��ht��kohtana oli Suomen logistinen asema ja mahdolliset kilpailukykyyn vaikuttavat tekij��t, joista on luotu potentiaalisia tulevaisuuden kuvia. Kaikki tulokset johdettiin LOADER/CLIENT ���tutkimusprojektin yhteyksist��. Tutkimuksen tavoitteisiin p����stiin empiirist�� tutkimusta varten kootun teorian kautta, joka koostuu toimitusketjun hallinnasta ja t��m��nhetkisest�� parhaimmasta k��yt��nn��st�� eli ns. kolmen A:n menetelm��st��. Lis��ksi teoriaosuudessa tarkasteltiin toimitusketjun yritysten v��lisi�� suhteita, kansainv��liseen toimitusketjuun liittyvi�� tekij��it�� sek�� tulevaisuuden haasteita. Ty��n empiirist�� tutkimustietoa ker��ttiin p����asiassa haastattelujen, mutta my��s muiden tutkimuksen tuloksien kautta. Tutkimusmenetelm�� oli laadullinen puolistrukturoitu teemahaastattelu, jota varten ryhm�� remontoimiseen ja saneeraukseen liittyvi�� yrityksi�� ja heid��n k��ytt��mi�� logistisia operaattoreita sek�� projektin johtoryhm���� haastateltiin. Tutkimuksen tulosten mukaan suurin osa haastatelluista yrityksist�� n��kee Suomen logistisen aseman hyv��n�� t��ll�� hetkell�� ja l��hivuosina. Etenkin arvotavaroiden transito- kuljetuksissa Suomen asema n��hd����n vahvana vuosien kokemuksen ansiosta. T��ll�� hetkell�� arvotavaroiden toimitusaika ja kokonaiskustannukset varastoimisineen ja k��sittelyineen ovat vastaavia tai jopa edullisempia verrattuna esimerkiksi reitteihin Baltian maiden kautta. Baltian maiden kehitys voi heikent���� Suomen kilpailukyky�� hetkellisesti, mutta todenn��k��isesti ei pidemm��ll�� aikav��lill��. Haastateltujen henkil��iden mielest�� Suomen logistiseen kilpailukykyyn tulevaisuudessa vaikuttaa eniten kaksi kriittist�� tekij����. Suomen tulisi ensinn��kin keskitty�� ja kehitt���� arvotavaran transitokuljetuksia. Toiseksi, s��ilytt����kseen kilpailukykyns��, Suomen satamien palveluiden kuten tullin ja ahtaajien tulisi olla joustavasti k��ytett��viss�� 24 tuntia vuorokaudessa vuoden jokaisena p��iv��n��.

Reuse of information for selection of methods and operating conditions for drying of pharmaceutical materials

Drying is a major step in the manufacturing process in pharmaceutical industries, and the selection of dryer and operating conditions are sometimes a bottleneck. In spite of difficulties, the bottlenecks are taken care of with utmost care due to good manufacturing practices (GMP) and industries' image in the global market. The purpose of this work is to research the use of existing knowledge for the selection of dryer and its operating conditions for drying of pharmaceutical materials with the help of methods like case-based reasoning and decision trees to reduce time and expenditure for research. The work consisted of two major parts as follows: Literature survey on the theories of spray dying, case-based reasoning and decision trees; working part includes data acquisition and testing of the models based on existing and upgraded data. Testing resulted in a combination of two models, case-based reasoning and decision trees, leading to more specific results when compared to conventional methods.

Pneumatic Conveying of Granular Materials in a Pilot Scale Downer-Riser System

Studies regarding the field of this work aim to substitute industrial mechanical conveyors with pneumatic conveyors to overcome the disadvantages in solids flow regulation and risks posed to production and health. The experimental part of this work examines how the granular material properties, fluidizing airflow rate, equipment geometry, and pressures along the pipes affect the mass flow rate through the system. The results are compared with those obtained from previous experiments conducted with alumina. Experiments were carried out with a pilot scale downer-riser system at Outotec Research Center Frankfurt. Granular materi-als used in this work are named as sand, ilmenite, iron ore 1 and iron ore 2.

Quality potential of DIP and hardwood CTMP based raw materials in woodcontaining printing paper

The objective of the thesis was to define the quality potential of DIP and hardwood CTMP based raw material furnish for a printing paper production and to define the end product's pulp-based boundary conditions especially when thinking of Chinese markets. Although the Chinese paper industry expands rapidly, the production of some paper grades is still exiguous. Especially the softwood resources are limited in Asia, thus the purpose of the thesis was to find out the possibilities to produce printing paper in China from local raw materials. Bleached CTMP can be produced, for example, from fast-growing hardwood species like eucalyptus and poplar. Therefore in this thesis it was examined if good quality printing paper is possible to produce by using deinked pulp and hardwood CTMP based furnish. In the first section of experimental part, various deinked pulps and chemithermomechanical pulps were compared. The deinked pulps were from China, Central Europe and Finland. Central European was made for magazine papers, and the Chinese as well as the Finnish pulps were made for newsprints. Two of the BCTMPs were from China and those both were made from poplar, whereas one BCTMP was made from eucalyptus in a pilot plant. There were significant differences especially between BCTMPs and their paper properties. In the second section of experimental part, the deinked pulp and eucalyptus BCTMP were blended to produce handsheets. The results show that producing the highest quality printing paper would be difficult from these raw materials. Deinked pulp affected especially the strength and optical properties as well as calender blackening. The BCTMP was found to have effects mostly on the smoothness, strength and optical properties as well as calender blackening.

Building the map of innovation for membrane materials (Ceramic membranes)

This work proposes a method of visualizing the trend of research in the field of ceramic membranes from 1999 to 2006. The presented approach involves identifying problems encountered during research in the field of ceramic membranes. Patents from US patent database and articles from Science Direct(& by ELSEVIER was analyzed for this work. The identification of problems was achieved with software Knowledgist which focuses on the semantic nature of a sentence to generate series of subject action object structures. The identified problems are classified into major research issues. This classification was used for the visualization of the intensity of research. The image produced gives the relation between the number of patents, with time and the major research issues. The identification of the most cited papers which strongly influence the research of the previously identified major issues in the given field was also carried out. The relations between these papers are presented using the metaphor of social network. The final result of this work are two figures, a diagram showing the change in the studied problems a specified period of time and a figure showing the relations between the major papers and groups of the problems

Elemental analysis of wood materials by external millibeam thick target PIXE

PIXE (Particle Induce X-ray Emission spectrometry) was used for analysing stem bark and stem wood of Scots pine, Norway spruce and Silver birch. Thick samples were irradiated, in laboratory atmosphere, with 3 MeV protons and the beam current was measured indirectly using a photo multiplicator (PM) tube. Both point scans and bulk analyses were performed with the 1 mm diameter proton beam. In bulk analyses, whole bark and sectors of discs of the stem wood were dry ashed at 550 ��C. The ashes were homogenised by shaking and prepared to target pellets for PIXE analyses. This procedure generated representative samples to be analysed, but the enrichment also enabled quantification of some additional trace elements. The ash contents obtained as a product of the sample preparation procedure also showed to be of great importance in the evaluation of results in environmental studies. Spot scans from the pith of pine wood outwards, showed clearly highest concentrations of manganese, calcium and zinc in the first spot irradiated, or 2-3 times higher than in the surrounding wood. For stem wood from the crown part of a pine this higher concentration level was found in the first four spots/mms, including the pith and the two following growth rings. Zinc showed increasing concentrations outwards in sapwood of the pine stem, with the over-all lowest concentrations in the inner half of the sapwood. This could indicate emigration of this element from sapwood being under transformation to heartwood. Point scans across sapwood of pine and spruce showed more distinct variations in concentrations relative to hearth wood. Higher concentrations of e.g. zinc, calcium and manganese were found in earlywood than in denser latewood. Very high concentrations of iron and copper were also seen for some earlywood increments. The ash content of stem bark is up to and order higher than for the stem wood. However, when the elemental concentration in ashes of bark and wood of the same disc were compared, these are very similar ��� this when trees are growing at spots with no anthropogenic contamination from the atmosphere. The largest difference was obtained for calcium which appeared at two times high concentrations in ashes of bark than in ashes of the wood (ratio of 2). Pine bark is often used in monitoring of atmospheric pollution, where concentrations in bark samples are compared. Here an alternative approach is suggested: Bark and the underlying stem wood of a pine trees are dry ashed and analysed. The elemental concentration in the bark ash is then compared to the concentration of the same element in the wood ash. Comparing bark to wood includes a normalisation for the varying availability of an element from the soil at different sites. When this comparison is done for the ashes of the materials, a normalisation is also obtained for the general and locally different enrichment of inorganic elements from wood to bark. Already a ratio >2 between the concentration in the bark ash and the concentration in the wood ash could indicate atmospheric pollution. For monitoring where bark is used, this way of ���inwards��� comparison is suggested - instead of comparing to results from analyses of bark from other trees (read reference areas), growing at sites with different soil and, locally, different climate conditions. This approach also enables evaluation of atmospheric pollution from sampling of only relative few individual trees ���preferable during forest felling.

Charge transport in disordered materials : simulations, theory, and numerical modeling of hopping transport and electron-hole recombination

Min avhandling behandlar hur oordnade material leder elektrisk str��m. Bland materialen som studeras finns ledande polymerer, d.v.s. plaster som leder str��m, och mer allm��nt organiska halvledare. Av de h��r materialen har man kunnat bygga elektroniska komponenter, och man hoppas p�� att kunna trycka hela kretsar av organiska material. F��r de h��r till��mpningarna ��r det viktigt att f��rst�� hur materialen sj��lva leder elektrisk str��m. Termen oordnade material syftar p�� material som saknar kristallstruktur. Oordningen g��r att elektronernas tillst��nd blir lokaliserade i rummet, s�� att en elektron i ett visst tillst��nd ��r begr��nsad t.ex. till en molekyl eller ett segment av en polymer. Det h��r kan j��mf��ras med kristallina material, d��r ett elektrontillst��nd ��r utspritt ��ver hela kristallen (men i st��llet har en v��ldefinierad r��relsem��ngd). Elektronerna (eller h��len) i det oordnade materialet kan r��ra sig genom att tunnelera mellan de lokaliserade tillst��nden. Utg��ende fr��n egenskaperna f��r den h��r tunneleringsprocessen, kan man best��mma transportegenskaperna f��r hela materialet. Det h��r ��r utg��ngspunkten f��r den s�� kallade hopptransportmodellen, som jag har anv��nt mig av. Hopptransportmodellen inneh��ller flera drastiska f��renklingar. Till exempel betraktas elektrontillst��nden som punktformiga, s�� att tunneleringssannolikheten mellan tv�� tillst��nd endast beror p�� avst��ndet mellan dem, och inte p�� deras relativa orientation. En annan f��renkling ��r att behandla det kvantmekaniska tunneleringsproblemet som en klassisk process, en slumpvandring. Trots de h��r grova approximationerna visar hopptransportmodellen ��nd�� m��nga av de fenomen som upptr��der i de verkliga materialen som man vill modellera. Man kan kanske s��ga att hopptransportmodellen ��r den enklaste modell f��r oordnade material som fortfarande ��r intressant att studera. Man har inte hittat exakta analytiska l��sningar f��r hopptransportmodellen, d��rf��r anv��nder man approximationer och numeriska metoder, ofta i form av datorber��kningar. Vi har anv��nt b��de analytiska metoder och numeriska ber��kningar f��r att studera olika aspekter av hopptransportmodellen. En viktig del av artiklarna som min avhandling baserar sig p�� ��r att j��mf��ra analytiska och numeriska resultat. Min andel av arbetet har fr��mst varit att utveckla de numeriska metoderna och applicera dem p�� hopptransportmodellen. D��rf��r fokuserar jag p�� den h��r delen av arbetet i avhandlingens introduktionsdel. Ett s��tt att studera hopptransportmodellen numeriskt ��r att direkt utf��ra en slumpvandringsprocess med ett datorprogram. Genom att f��ra statisik ��ver slumpvandringen kan man ber��kna olika transportegenskaper i modellen. Det h��r ��r en s�� kallad Monte Carlo-metod, eftersom sj��lva ber��kningen ��r en slumpm��ssig process. I st��llet f��r att f��lja r��relsebanan f��r enskilda elektroner, kan man ber��kna sannolikheten vid j��mvikt f��r att hitta en elektron i olika tillst��nd. Man st��ller upp ett system av ekvationer, som relaterar sannolikheterna f��r att hitta elektronen i olika tillst��nd i systemet med fl��det, str��mmen, mellan de olika tillst��nden. Genom att l��sa ekvationssystemet f��s sannolikhetsf��rdelningen f��r elektronerna. Fr��n sannolikhetsf��rdelningen kan sedan str��mmen och materialets transportegenskaper ber��knas. En aspekt av hopptransportmodellen som vi studerat ��r elektronernas diffusion, d.v.s. deras slumpm��ssiga r��relse. Om man betraktar en samling elektroner, s�� sprider den med tiden ut sig ��ver ett st��rre omr��de. Det ��r k��nt att diffusionshastigheten beror av elf��ltet, s�� att elektronerna sprider sig fortare om de p��verkas av ett elektriskt f��lt. Vi har unders��kt den h��r processen, och visat att beteendet ��r v��ldigt olika i endimensionella system, j��mf��rt med tv��- och tredimensionella. I tv�� och tre dimensioner beror diffusionskoefficienten kvadratiskt av elf��ltet, medan beroendet i en dimension ��r linj��rt. En annan aspekt vi studerat ��r negativ differentiell konduktivitet, d.v.s. att str��mmen i ett material minskar d�� man ��kar sp��nningen ��ver det. Eftersom det h��r fenomenet har uppm��tts i organiska minnesceller, ville vi unders��ka om fenomenet ocks�� kan uppst�� i hopptransportmodellen. Det visade sig att det i modellen finns tv�� olika mekanismer som kan ge upphov till negativ differentiell konduktivitet. Dels kan elektronerna fastna i f��llor, ��terv��ndsgr��nder i systemet, som ��r s��dana att det ��r sv��rare att ta sig ur dem d�� elf��ltet ��r stort. D�� kan elektronernas medelhastighet och d��rmed str��mmen i materialet minska med ��kande elf��lt. Elektrisk v��xelverkan mellan elektronerna kan ocks�� leda till samma beteende, genom en s�� kallad coulombblockad. En coulombblockad kan uppst�� om antalet ledningselektroner i materialet ��kar med ��kande sp��nning. Elektronerna repellerar varandra och ett st��rre antal elektroner kan leda till att transporten blir l��ngsammare, d.v.s. att str��mmen minskar.

Defects in Persistent Luminescence Materials

Persistent luminescence materials can store energy from solar radiation or artificial lighting and release it over a period of several hours without a continuous excitation source. These materials are widely used to improve human safety in emergency and traffic signalization. They can also be utilized in novel applications including solar cells, medical diagnostics, radiation detectors and structural damage sensors. The development of these materials is currently based on methods based on trial and error. The tailoring of new materials is also hindered by the lack of knowledge on the role of their intrinsic and extrinsic lattice defects in the appropriate mechanisms. The goal of this work was to clarify the persistent luminescence mechanisms by combining <i>ab initio</i> density functional theory (DFT) calculations with selected experimental methods. The DFT approach enables a full control of both the nature of the defects and their locations in the host lattice. The materials studied in the present work, the distrontium magnesium disilicate (Sr₂MgSi₂O₇) and strontium aluminate (SrAl₂O₄) are among the most efficient persistent luminescence hosts when doped with divalent europium Eu²⁺ and co-doped with trivalent rare earth ions R³⁺ (R: Y, La-Nd, Sm, Gd-Lu). The polycrystalline materials were prepared with the solid state method and their structural and phase purity was confirmed by X-ray powder diffraction. Their local crystal structure was studied by high-resolution transmission electron microscopy. The crystal and electronic structure of the nondoped as well as Eu²⁺, R^2+/3+ and other defect containing materials were studied using DFT calculations. The experimental trap depths were obtained using thermoluminescence (TL) spectroscopy. The emission and excitation of Sr₂MgSi₂O₇:Eu²+,</sup>Dy³⁺ were also studied. Significant modifications in the local crystal structure due to the Eu²⁺ ion and lattice defects were found by the experimental and DFT methods. The charge compensation effects induced by the R³⁺ co-doping further increased the number of defects and distortions in the host lattice. As for the electronic structure of Sr₂MgSi₂O₇ and SrAl₂O₄, the experimental band gap energy of the host materials was well reproduced by the calculations. The DFT calculated Eu²⁺ and R^2+/3+ 4fn as well as 4f^n-15d¹ ground states in the Sr₂MgSi₂O₇ band structure provide an independent verification for an empirical model which is constructed using rather sparse experimental data for the R³⁺ and especially the R²⁺ ions. The intrinsic and defect induced electron traps were found to act together as energy storage sites contributing to the materials��� efficient persistent luminescence. The calculated trap energy range agreed with the trap structure of Sr₂MgSi₂O₇ obtained using TL measurements. More experimental studies should be carried out for SrAl₂O₄ to compare with the DFT calculations. The calculated and experimental results show that the electron traps created by both the rare earth ions and vacancies are modified due to the defect aggregation and charge compensation effects. The relationships between this modification and the energy storage properties of the solid state materials are discussed.