The Effects of Some Furnish and Paper Structure Related Factors on Wet Web Tensile and Relaxation Characteristics

The objective of this thesis was to identify the effects of different factors on the tension and tension relaxation of wet paper web after high-speed straining. The study was motivated by the plausible connection between wet web mechanical properties and wet web runnability on paper machines shown by previous studies. The mechanical properties of wet paper were examined using a fast tensile test rig with a strain rate of 1000%/s. Most of the tests were carried out with laboratory handsheets, but samples from a pilot paper machine were also used. The tension relaxation of paper was evaluated as the tension remaining after 0.475 s of relaxation (residual tension). The tensile and relaxation properties of wet webs were found to be strongly dependent on the quality and amount of fines. With low fines content, the tensile strength and residual tension of wet paper was mainly determined by the mechanical interactions between fibres at their contact points. As the fines strengthen the mechanical interaction in the network, the fibre properties also become important. Fibre deformations caused by the mechanical treatment of pulp were shown to reduce the mechanical properties of both dry and wet paper. However, the effect was significantly higher for wet paper. An increase of filler content from 10% to 25% greatly reduced the tensile strength of dry paper, but did not significantly impair wet web tensile strength or residual tension. Increased filler content in wet web was shown to increase the dryness of the wet web after the press section, which partly compensates for the reduction of fibrous material in the web. It is also presumable that fillers increase entanglement friction between fibres, which is beneficial for wet web strength. Different contaminants present in white water during sheet formation resulted in lowered surface tension and increased dryness after wet pressing. The addition of different contaminants reduced the tensile strength of the dry paper. The reduction of dry paper tensile strength could not be explained by the reduced surface tension, but rather on the tendency of different contaminants to interfere with the inter-fibre bonding. Additionally, wet web strength was not affected by the changes in the surface tension of white water or possible changes in the hydrophilicity of fibres caused by the addition of different contaminants. The spraying of different polymers on wet paper before wet pressing had a significant effect on both dry and wet web tensile strength, whereas wet web elastic modulus and residual tension were basically not affected. We suggest that the increase of dry and wet paper strength could be affected by the molecular level interactions between these chemicals and fibres. The most significant increases in dry and wet paper strength were achieved with a dual application of anionic and cationic polymers. Furthermore, selectively adding papermaking chemicals to different fibre fractions (as opposed to adding chemicals to the whole pulp) improved the wet web mechanical properties and the drainage of the pulp suspension.

Capital structure of Finnish firms – Estimating the effects of firm characteristics on capital structure

One of the most disputable matters in the theory of finance has been the theory of capital structure. The seminal contributions of Modigliani and Miller (1958, 1963) gave rise to a multitude of studies and debates. Since the initial spark, the financial literature has offered two competing theories of financing decision: the trade-off theory and the pecking order theory. The trade-off theory suggests that firms have an optimal capital structure balancing the benefits and costs of debt. The pecking order theory approaches the firm capital structure from information asymmetry perspective and assumes a hierarchy of financing, with firms using first internal funds, followed by debt and as a last resort equity. This thesis analyses the trade-off and pecking order theories and their predictions on a panel data consisting 78 Finnish firms listed on the OMX Helsinki stock exchange. Estimations are performed for the period 2003–2012. The data is collected from Datastream system and consists of financial statement data. A number of capital structure characteristics are identified: firm size, profitability, firm growth opportunities, risk, asset tangibility and taxes, speed of adjustment and financial deficit. A regression analysis is used to examine the effects of the firm characteristics on capitals structure. The regression models were formed based on the relevant theories. The general capital structure model is estimated with fixed effects estimator. Additionally, dynamic models play an important role in several areas of corporate finance, but with the combination of fixed effects and lagged dependent variables the model estimation is more complicated. A dynamic partial adjustment model is estimated using Arellano and Bond (1991) first-differencing generalized method of moments, the ordinary least squares and fixed effects estimators. The results for Finnish listed firms show support for the predictions of profitability, firm size and non-debt tax shields. However, no conclusive support for the pecking-order theory is found. However, the effect of pecking order cannot be fully ignored and it is concluded that instead of being substitutes the trade-off and pecking order theory appear to complement each other. For the partial adjustment model the results show that Finnish listed firms adjust towards their target capital structure with a speed of 29% a year using book debt ratio.

Galvanomagnetic effects in strongly doped p-Bi2Te3:Sn crystals

Magnetic field dependencies of Hall coefficient and magnetoresistivity are investigated in classical and quantizing magnetic fields in p-Bi2Te3 crystals heavily doped with Sn grown by Czochralsky method. Magnetic field was parallel to the trigonal axis C3. Shubnikov-de Haas effect and quantum oscillations of the Hall coefficient were measured at temperatures 4.2 K and 11 K. On the basis of the magnetic field dependence of the Hall coefficient a method of estimation of the Hall factor and Hall mobility using the Drabble- Wolf six ellipsoid model is proposed. Shubnikov-de Haas effect and quantum oscillations of the Hall coefficient were observed at 4.2 K and 11 K. New evidence for the existence of the narrow band of Sn impurity states was shown. This band is partly filled by electrons and it is overlapping with the valence states of the light holes. Parameters of the impurity states, their energy ESn - 15 meV, band broadening ¿<< k0T and localization radius of the impuritystate R - 30 Å were obtained.

Effects of mergers and acquisitions in the paper industry

Paperiteollisuus on ollut perinteisesti fragmentoitunut toimiala, mutta viime vuosikymmenen aikana konsolidoitumisprosessi on kiihtynyt. Yrityskaupat ja fuusiot ovat muuttaneet paperiteollisuuden markkinarakennetta merkittävästi. Työn tavoitteena oli tutkia yleisesti markkinarakenteen vaikutusta liiketoiminnan tuloksiin sekä analysoida yrityskauppojen ja fuusioiden syitä, tuloksia ja rajoituksia. Tavoitteena oli myös tutkia paperiteollisuuden konsolidoitumisen vaikutuksia hintakehitykseen, hintaheilahteluihin ja kannattavuuteen. Keskeisenä syynä konsolidoitumiskehitykselle voidaan pitää uusien paperikoneiden huomattavaa investointikustannusten kasvua. Toinen tärkeä tekijä yhdentymiskehitykselle on se, että paperiteollisuus on saavuttanut elinkaaren kypsyysvaiheen Euroopassa, Pohjois-Amerikassa ja Japanissa. Yrityskauppojen ja fuusioiden motiiveja paperiteollisuudessa ovat mm. kasvu kypsillä markkinoilla, tarve parantaa taloudellista tulosta, mahdollisuus toimia globaalisti ja hyödyntää siitä saatavat edut tai mahdollisuus parempaan arvoketjun hallintaan. Näyttää siltä, että suurempien paperiteollisuusyritysten kannattavuus ei ole parempi kuin pienemmillä yrityksillä. Lisäksi useimmissa paperiteollisuuden yrityskaupoissa ja fuusioissa näyttäisi ostavan osapuolen kurssikehitys ilmoitusta seuraavana päivänä olevan negatiivinen.

Capital Structure of Finnish SMEs and Financial Constraints

This thesis studies capital structure of Finnish small and medium sized enterprises. The specific object of the study is to test whether financial constraints have an effect on capital structure. In addition influences of several other factors were studied. Capital structure determinants are formulated based on three capital structure theories. The tradeoff theory and the agency theory concentrate on the search of optimal capital structure. The pecking order theory concerns favouring on financing source over another. The data of this study consists of financial statement data and results of corporate questionnaire. Regression analysis was used to find out the effects of several determinants. Regression models were formed based on the presented theories. Short and long term debt ratios were considered separately. The metrics of financially constrained firms was included in all models. It was found that financial constrains have a negative and significant effect to short term debt ratios. The effect was negative also to long term debt ratio but not statistically significant. Other considerable factors that influenced debt ratios were fixed assets, age, profitability, single owner and sufficiency of internal financing.

The effects of social networks on work-team effectiveness

This is a study of team social networks, their antecedents and outcomes. In focusing attention on the structural configuration of the team this research contributes to a new wave of thinking concerning group social capital. The research site was a random sample of Finnish work organisations. The data consisted of 499 employees in 76 teams representing 48 different organisations. A systematic literature review and quantitative methods were used in conducting the research: the former primarily to establish the current theoretical position on the relationships among the variables and the latter to test these relationships. Social network analysis was the primary method used in identifying the social-network relations among the work-team members. The first and key contribution of this study is that it relates the structuralnetwork properties of work teams to behavioural outcomes, attitudinal outcomes and, ultimately, team performance. Moreover, it shows that addressing attitudinal outcomes is also important in terms of team performance; attitudinal outcomes (team identity) mediated the relationship between the team’s performance and its social network. The second contribution is that it examines the possible antecedents of the social structure. It is thus one response to Salancik’s (1995) call for a network theory in that it explains why certain network characteristics exist. Itdemonstrates that irrespective of whether or not a team is heterogeneous in terms of age or gender, educational diversity may protect it from centralisation. However, heterogeneity in terms of gender turned out to have a negative impact on density. Thirdly, given the observation that the benefits of (team) networks are typically theorised and modelled without reference to the nature of the relationships comprising the structure, the study directly tested whether team knowledge mediated the effects of instrumental and expressive network relationships on team performance. Furthermore, with its focus on expressive networks that link the workplace to a more informal world, which have been rather neglected in previous research, it enhances knowledge of teams andnetworks. The results indicate that knowledge sharing fully mediates the influence of complementarities between dense and fragmented instrumental network relationships, thus providing empirical validation of the implicit understanding that networks transfer knowledge. Fourthly, the study findings suggest that an optimal configuration of the work-team social-network structure combines both bridging and bonding social relationships.

The determination of EONIA rate: The impact of the financial crisis and the effects of the changes in the monetary policy implementation framework

EONIA is a market based overnight interest rate, whose role as the starting point of the yield curve makes it critical from the perspective of the implementation of European Central Bank´s common monetary policy in the euro area. The financial crisis that started in 2007 had a large impact on the determination mechanism of this interest rate, which is considered as the central bank´s operational target. This thesis examines the monetary policy implementation framework of the European Central Bank and changes made to it. Furthermore, we discuss the development of the recent turmoil in the money market. EONIA rate is modelled by means of a regression equation using variables related to liquidity conditions, refinancing need, auction results and calendar effects. Conditional volatility is captured by an EGARCH model, and autocorrelation is taken into account by employing an autoregressive structure. The results highlight how the tensions in the initial stage of the market turmoil were successfully countered by ECB´s liquidity policy. The subsequent response of EONIA to liquidity conditions under the full allotment liquidity provision procedure adopted after the demise of Lehman Brothers is also established. A clear distinction in the behavior of the interest rate between the sub-periods was evident. In the light of the results obtained, some of the challenges posed by the exit-strategy implementation will be addressed.

Influence of plasma modification on surface properties and offset printability of coated paper

The properties of the paper surface play a crucial role in ensuring suitable quality and runnability in various converting and finishing operations, such as printing. Plasma surface modification makes it possible to modify the surface chemistry of paper without altering the bulk material properties. This also makes it possible to investigate the role of the surface chemistry alone on printability without influencing the porous structure of the pigment-coated paper. Since the porous structure of a pigment coating controls both ink setting and optical properties, surface chemical changes created by a plasma modification have a potential to decouple these two effects and to permit a better optimization of them both. The aim of this work was to understand the effects of plasma surface modification on paper properties, and how it influences printability in the sheet-fed offset process. The objective was to broaden the fundamental understanding of the role of surface chemistry on offset printing. The effects of changing the hydrophilicity/ hydrophobicity and the surface chemical composition by plasma activation and plasma coatings on the properties of coated paper and on ink-paper interactions as well as on sheet-fed offset print quality were investigated. In addition, the durability of the plasma surface modification was studied. Nowadays, a typical sheet-fed offset press also contains units for surface finishing, for example UVvarnishing. The role of the surface chemistry on the UV-varnish absorption into highly permeable and porous pigment-coated paper was also investigated. With plasma activation it was possible to increase the surface energy and hydrophilicity of paper. Both polar and dispersion interactions were found to increase, although the change was greater in the polar interactions due to induced oxygen molecular groups. The results indicated that plasma activation takes place particularly in high molecular weight components such as the dispersion chemicals used to stabilize the pigment and latex particles. Surface composition, such as pigment and binder type, was found to influence the response to the plasma activation. The general trend was that pilot-scale treatment modified the surface chemistry without altering the physical coating structure, whereas excessive laboratory-scale treatment increased the surface roughness and reduced the surface strength, which led to micro-picking in printing. It was shown that pilot-scale plasma activation in combination with appropriate ink oils makes it possible to adjust the ink-setting rate. The ink-setting rate decreased with linseed-oil-based inks, probably due to increased acid-base interactions between the polar groups in the oil and the plasma-treated paper surface. With mineral-oil-based inks, the ink setting accelerated due to plasma activation. Hydrophobic plasma coatings were able to reduce or even prevent the absorption of dampening water into pigmentcoated paper, even when the dampening water was applied under the influence of nip pressure. A uniform hydrophobic plasma coating with sufficient chemical affinity with ink gave an improved print quality in terms of higher print density and lower print mottle. It was also shown that a fluorocarbon plasma coating reduced the free wetting of the UV-varnish into the highly permeable and porous pigment coating. However, when the UV-varnish was applied under the influence of nip pressure, which leads to forced wetting, the role of the surface chemical composition seems to be much less. A decay in surface energy and wettability occurred during the first weeks of storage after plasma activation, after which it leveled off. However, the oxygen/carbon elemental ratio did not decrease as a function of time, indicating that ageing could be caused by a re-orientation of polar groups or by a contamination of the surface. The plasma coatings appeared to be more stable when the hydrophobicity was higher, probably due to fewer interactions with oxygen and water vapor in the air.

Alpha2-adrenoceptors: Structure and ligand binding properties at the molecular level

Alpha₂-Adrenoceptors: structure and ligand binding properties at the molecular level The mouse is the most frequently used animal model in biomedical research, but the use of zebrafish as a model organism to mimic human diseases is on the increase. Therefore it is considered important to understand their pharmacological differences from humans also at the molecular level. The zebrafish Alpha_2-adrenoceptors were expressed in mammalian cells and the binding affinities of 20 diverse ligands were determined and compared to the corresponding human receptors. The pharmacological properties of the human and zebrafish Alpha_2--adrenoceptors were found to be quite well conserved. Receptor models based on the crystal structures of bovine rhodopsin and the human Beta₂-adrenoceptor revealed that most structural differences between the paralogous and orthologous Alpha_2--adrenoceptors were located within the second extracellular loop (XL2). Reciprocal mutations were generated in the mouse and human Alpha_2--adrenoceptors. Ligand binding experiments revealed that substitutions in XL2 reversed the binding profiles of the human and mouse Alpha_2--adrenoceptors for yohimbine, rauwolscine and RS-79948-197, evidence for a role for XL2 in the determination of species-specific ligand binding. Previous mutagenesis studies had not been able to explain the subtype preference of several large Alpha_2--adrenoceptor antagonists. We prepared chimaeric Alpha_2--adrenoceptors where the first transmembrane (TM1) domain was exchanged between the three human Alpha_2--adrenoceptor subtypes. The binding affinities of spiperone, spiroxatrine and chlorpromazine were observed to be significantly improved by TM1 substitutions of the Alpha_2a--adrenoceptor. Docking simulations indicated that indirect effects, such as allosteric modulation, are more likely to be involved in this phenomenon rather than specific side-chain interactions between ligands and receptors.

Quantum Hall effect in 2 dimensional GaInAs structure

Transport properties of GaAs / δ – Mn / GaAs / InxGa1-xAs / GaAs structure with Mn δ – layer, which is separated from InxGa1-xAs quantum well (QW) by 3 nm thick GaAs spacer was investigated. This structure with high mobility was characterized by X-ray difractometry and reflectometry. Transport and electrical properties of the structure were measured by using Pulsed Magnetic Field System (PMFS). During investigation of the Shubnikov – de Haas and the Hall effects the main parameters of QW structure such as cyclotron mass, Fermi level, g – factor, Dingle temperature and concentration of holes were estimated. Obtained results show high quality of the prepared structure. However, anomalous Hall effect at temperatures 2.09 K, 3 K, 4.2 K is not clearly observed. Attempts to identify magnetic moment were made. For this purpose the polarity of the filed was changed to the opposite at each shot. As a result hysteresis loop was not observed in the magnetic field dependences of the anomalous Hall resistivity.This can be attributed to the imperfection of the experimental setup.

Galvanomagnetic effects in InGaAs nanostructure

Investigation of galvanomagnetic effects in nanostructure GaAs/Mn/GaAs/In0.15Ga0.85As/ GaAs is presented. This nanostructure is classified as diluted magnetic semiconductor (DMS). Temperature dependence of transverse magnetoresistivity of the sample was studied. The anomalous Hall effect was detected and subtracted from the total Hall component. Special attention was paid to the measurements of Shubnikov-de Haas oscillations, which exists only in the case of magnetic field aligned perpendicularly to the plane of the sample. This confirms two-dimensional character of the hole energy spectrum in the quantum well. Such important characteristics as cyclotron mass, the Fermi energy and the Dingle temperature were calculated, using experimental data of Shubnikov-de Haas oscillations. The hole concentration and hole mobility in the quantum well also were estimated for the sample. At 4.2 K spin splitting of the maxima of transverse resistivity was observed and g-factor was calculated for that case. The values of the Dingle temperatures were obtained by two different approaches. From the comparison of these values it was concluded that the broadening of Landau levels in the investigated structure is mainly defined by the scattering of charge carriers on the defects of the crystal lattice

Manifestation of the pairing symmetry in the vortex core structure in iron-based superconductors

The superconducting gap is a basic character of a superconductor. While the cuprates and conventional phonon-mediated superconductors are characterized by distinct d- and s-wave pairing symmetries with nodal and nodeless gap distributions respectively, the superconducting gap distributions in iron-based superconductors are rather diversified. While nodeless gap distributions have been directly observed in Ba1–xKxFe2As2, BaFe2–xCoxAs2, LiFeAs, KxFe2–ySe2, and FeTe1–xSex, the signatures of a nodal superconducting gap have been reported in LaOFeP, LiFeP, FeSe, KFe2As2, BaFe2–xRuxAs2, and BaFe2(As1–xPx)2. Due to the multiplicity of the Fermi surface in these compounds s± and d pairing states can be both nodeless and nodal. A nontrivial orbital structure of the order parameter, in particular the presence of the gap nodes, leads to effects in which the disorder is much richer in dx2–y2-wave superconductors than in conventional materials. In contrast to the s-wave case, the Anderson theorem does not work, and nonmagnetic impurities exhibit a strong pair-breaking influence. In addition, a finite concentration of disorder produces a nonzero density of quasiparticle states at zero energy, which results in a considerable modification of the thermodynamic and transport properties at low temperatures. The influence of order parameter symmetry on the vortex core structure in iron-based pnictide and chalcogenide superconductors has been investigated in the framework of quasiclassical Eilenberger equations. The main results of the thesis are as follows. The vortex core characteristics, such as, cutoff parameter, ξh, and core size, ξ2, determined as the distance at which density of the vortex supercurrent reaches its maximum, are calculated in wide temperature, impurity scattering rate, and magnetic field ranges. The cutoff parameter, ξh(B; T; Г), determines the form factor of the flux-line lattice, which can be obtained in _SR, NMR, and SANS experiments. A comparison among the applied pairing symmetries is done. In contrast to s-wave systems, in dx2–y2-wave superconductors, ξh/ξc2 always increases with the scattering rate Г. Field dependence of the cutoff parameter affects strongly on the second moment of the magnetic field distributions, resulting in a significant difference with nonlocal London theory. It is found that normalized ξ2/ξc2(B/Bc2) dependence is increasing with pair-breaking impurity scattering (interband scattering for s±-wave and intraband impurity scattering for d-wave superconductors). Here, ξc2 is the Ginzburg-Landau coherence length determined from the upper critical field Bc2 = Φ0/2πξ2 c2, where Φ0 is a flux quantum. Two types of ξ2/ξc2 magnetic field dependences are obtained for s± superconductors. It has a minimum at low temperatures and small impurity scattering transforming in monotonously decreasing function at strong scattering and high temperatures. The second kind of this dependence has been also found for d-wave superconductors at intermediate and high temperatures. In contrast, impurity scattering results in decreasing of ξ2/ξc2(B/Bc2) dependence in s++ superconductors. A reasonable agreement between calculated ξh/ξc2 values and those obtained experimentally in nonstoichiometric BaFe2–xCoxAs2 (μSR) and stoichiometric LiFeAs (SANS) was found. The values of ξh/ξc2 are much less than one in case of the first compound and much more than one for the other compound. This is explained by different influence of two factors: the value of impurity scattering rate and pairing symmetry.

Membrane properties of structurally modified ceramides : effects on lipid lateral distribution and sphingomyelin-interactions in artificial bilayer membranes

Ceramides comprise a class of sphingolipids that exist only in small amounts in cellular membranes, but which have been associated with important roles in cellular signaling processes. The influences that ceramides have on the physical properties of bilayer membranes reach from altered thermodynamical behavior to significant impacts on the molecular order and lateral distribution of membrane lipids. Along with the idea that the membrane physical state could influence the physiological state of a cell, the membrane properties of ceramides have gained increasing interest. Therefore, membrane phenomena related to ceramides have become a subject of intense study both in cellular as well as in artificial membranes. Artificial bilayers, the so called model membranes, are substantially simpler in terms of contents and spatio-temporal variation than actual cellular membranes, and can be used to give detailed information about the properties of individual lipid species in different environments. This thesis focuses on investigating how the different parts of the ceramide molecule, i.e., the N-linked acyl chain, the long-chain sphingoid base and the membrane-water interface region, govern the interactions and lateral distribution of these lipids in bilayer membranes. With the emphasis on ceramide/sphingomyelin(SM)-interactions, the relevance of the size of the SMhead group for the interaction was also studied. Ceramides with methylbranched N-linked acyl chains, varying length sphingoid bases, or methylated 2N (amide-nitrogen) and 3O (C3-hydroxyl) at the interface region, as well as SMs with decreased head group size, were synthesized and their bilayer properties studied by calorimetric and fluorescence spectroscopic techniques. In brief, the results showed that the packing of the ceramide acyl chains was more sensitive to methyl-branching in the mid part than in the distal end of the N-linked chain, and that disrupting the interfacial structure at the amide-nitrogen, as opposed to the C3-hydroxyl, had greater effect on the interlipid interactions of ceramides. Interestingly, it appeared that the bilayer properties of ceramides could be more sensitive to small alterations in the length of the long-chain base than what was previously reported for the N-linked acyl chain. Furthermore, the data indicated that the SM-head group does not strongly influence the interactions between SMs and ceramides. The results in this thesis illustrate the pivotal role of some essential parts of the ceramide molecules in determining their bilayer properties. The thesis provides increased understanding of the molecular aspects of ceramides that possibly affect their functions in biological membranes, and could relate to distinct effects on cell physiology.

Surface characterization of chemically modified fiber, wood and paper

Inorganic-organic sol-gel hybrid coatings can be used for improving and modifying properties of wood-based materials. By selecting a proper precursor, wood can be made water repellent, decay-, moisture- or UV-resistant. However, to control the barrier properties of sol-gel coatings on wood substrates against moisture uptake and weathering, an understanding of the surface morphology and chemistry of the deposited sol-gel coatings on wood substrates is needed. Mechanical pulp is used in production of wood-containing printing papers. The physical and chemical fiber surface characteristics, as created in the chosen mechanical pulp manufacturing process, play a key role in controlling the properties of the end-use product. A detailed understanding of how process parameters influence fiber surfaces can help improving cost-effectiveness of pulp and paper production. The current work focuses on physico-chemical characterization of modified wood-based materials with surface sensitive analytical tools. The overall objectives were, through advanced microscopy and chemical analysis techniques, (i) to collect versatile information about the surface structures of Norway spruce thermomechanical pulp fiber walls and understand how they are influenced by the selected chemical treatments, and (ii) to clarify the effect of various sol-gel coatings on surface structural and chemical properties of wood-based substrates. A special emphasis was on understanding the effect of sol-gel coatings on the water repellency of modified wood and paper surfaces. In the first part of the work, effects of chemical treatment on micro- and nano-scale surface structure of 1st stage TMP latewood fibers from Norway spruce were investigated. The chemicals applied were buffered sodium oxalate and hydrochloric acid. The outer and the inner fiber wall layers of the untreated and chemically treated fibers were separately analyzed by light microscopy, atomic force microscopy and field-emission scanning electron microscopy. The selected characterization methods enabled the demonstration of the effect of different treatments on the fiber surface structure, both visually and quantitatively. The outer fiber wall areas appeared as intact bands surrounding the fiber and they were clearly rougher than areas of exposed inner fiber wall. The roughness of the outer fiber wall areas increased most in the sodium oxalate treatment. The results indicated formation of more surface pores on the exposed inner fiber wall areas than on the corresponding outer fiber wall areas as a result of the chemical treatments. The hydrochloric acid treatment seemed to increase the surface porosity of the inner wall areas. In the second part of the work, three silane-based sol-gel hybrid coatings were selected in order to improve moisture resistance of wood and paper substrates. The coatings differed from each other in terms of having different alkyl (CH3–, CH3-(CH2)7–) and fluorocarbon (CF3–) chains attached to the trialkoxysilane sol-gel precursor. The sol-gel coatings were deposited by a wet coating method, i.e. spraying or spreading by brush. The effect of solgel coatings on surface structural and chemical properties of wood-based substrates was studied by using advanced surface analyzing tools: atomic force microscopy, X-ray photoelectron spectroscopy and time-of-flight secondary ion spectroscopy. The results show that the applied sol-gel coatings, deposited as thin films or particulate coatings, have different effects on surface characteristics of wood and wood-based materials. The coating which has a long hydrocarbon chain (CH3-(CH2)7–) attached to the silane backbone (octyltriethoxysilane) produced the highest hydrophobicity for wood and wood-based materials.