Influence of changes in crop cultivation areas on pollen contents of honey

Selostus: Viljelyalojen muutosten vaikutus hunajan siitepölysisältöön

Influence of nitrogen deficiency on photosynthesis and chloroplast ultrastructure of pepper plants

Selostus: Typen puutteen vaikutus paprikan fotosynteesiin ja kloroplastien rakenteeseen

Influence of pre partum and post partum plane of nutrition on the performance of crossbred suckler cows and their progeny

Selostus: Sisäruokintakauden energiamäärien vaikutus risteytysemolehmien tuotantoon

Influence of silvicultural regime on wood structure characteristics and mechanical properties of clear wood in Pinus sylvestris

Abstract

Influence Of AirContent On Board Properties

Työn tarkoitus oli testata kartonkikoneen lyhyen kierron ilmapitoisuuden merkitystä kartongin ominaisuuksiin. Aluksi työssä selvitettiin ilmapitoisuuden alkutilanne käyttäen kompressioilmiöön perustuvaa ilmapitoisuusmittaria. Sen jälkeen tehtiin kokeita käyttäen POMp-pumppua sekä vaahdonestoainetta. Tarkoituksena oli luoda yhteys prosessin ilmapitoisuuden ja lopputuotteen ominaisuuksien välille. POMp-kokeissa tutkittiin keskipakopumppauksen vaikutusta massan ilmapitoisuuteen. Tuloksista nähdään, että pintakerroksen ilmapitoisuus oli suurempi kuin taustakerroksen, mikä selittyy POMp-pumpun sijainnilla taustakerroksen lyhyessä kierrossa. Vaahdonestoainekokeissa saatiin myös vaikutuksia massan ilmapitoisuuteen. Vaahdonestoaineen lisäyksen jälkeen runkokerroksenilmapitoisuus laski, kun samanaikaisesti pinta- ja taustakerroksen sekä rejektisysteemin ilmapitoisuudet nousivat. Ilmapitoisuuden käytöksen syyksi paljastui lyhyen kierron yhteinen vesikierto ja nykyisille tuotantomäärille alimitoitettu ilmanpoistokapasiteetti. Vaahdonestoaineen lisäyksen jälkeen vedenpoisto parani ja ensimmäisillä kolmella runkokerroksen foililaatikolla havaittiin poistuvan veden virtausten kasvaneen. Samaan aikaan runkokerroksen viiraosan lopulla poistuvan veden virtaukset pienenivät. Kartongin ominaisuuksissa ei havaittu kuitenkaan eroa, vaikka vedenpoisto parani viiraosalla selvästi. Vaahdonestoainekokeiden aikana oli myös tavallista enemmän ajettavuusongelmia, kuten ratakatkoja. Prosessissa esiintyneitä ongelmia ja niihin reagoivia muutosehdotuksia esitellään myös. Vaikein ongelma oli ilman muodostuminen runkokerroksen lyhyessä kierrossa. Ratkaisu voisi koostua isommasta keskikerroksenvesilukkosäiliöstä ja runkokerroksen lyhyen kierron puhdistusveden uudelleen kohdentamisesta. Voisi myös olla hyödyllistä yrittää ilmanpoistoa kemikaalien avulla kiertoveden varastosäiliössä.

Influence of stationary phase and eluent properties on chromatographic separation of carbohydrates

In this thesis, the sorption and elastic properties of the cation-exchange resins were studied to explain the liquid chromatographic separation of carbohydrates. Na+, Ca2+ and La3+ form strong poly(styrene-co-divinylbenzene) (SCE) as well as Na+ and Ca2+ form weak acrylic (WCE) cation-exchange resins at different cross-link densities were treated within this work. The focus was on the effects of water-alcohol mixtures, mostly aqueous ethanol, and that of the carbohydrates. The carbohydrates examined were rhamnose, xylose, glucose, fructose, arabinose, sucrose, xylitol and sorbitol. In addition to linear chromatographic conditions, non-linear conditions more typical for industrial applications were studied. Both experimental and modeling aspectswere covered. The aqueous alcohol sorption on the cation-exchangers were experimentally determined and theoretically calculated. The sorption model includes elastic parameters, which were obtained from sorption data combined with elasticity measurements. As hydrophilic materials cation-exchangers are water selective and shrink when an organic solvent is added. At a certain deswelling degree the elastic resins go through glass transition and become as glass-like material. Theincreasing cross-link level and the valence of the counterion decrease the sorption of solvent components in the water-rich solutions. The cross-linkage or thecounterions have less effect on the water selectivity than the resin type or the used alcohol. The amount of water sorbed is higher in the WCE resin and, moreover, the WCE resin is more water selective than the corresponding SCE resin. Theincreased aliphatic part of lower alcohols tend to increase the water selectivity, i.e. the resins are more water selective in 2-propanol than in ethanol solutions. Both the sorption behavior of carbohydrates and the sorption differences between carbohydrates are considerably affected by the eluent composition and theresin characteristics. The carbohydrate sorption was experimentally examined and modeled. In all cases, sorption and moreover the separation of carbohydrates are dominated by three phenomena: partition, ligand exchange and size exclusion. The sorption of hydrophilic carbohydrates increases when alcohol is added into the eluent or when carbohydrate is able to form coordination complexes with the counterions, especially with multivalent counterions. Decreasing polarity of the eluent enhances the complex stability. Size exclusion effect is more prominent when the resin becomes tighter or carbohydrate size increases. On the other hand,the elution volumes between different sized carbohydrates decreases with the decreasing polarity of the eluent. The chromatographic separation of carbohydrateswas modeled, using rhamnose and xylose as target molecules. The thermodynamic sorption model was successfully implemented in the rate-based column model. The experimental chromatographic data were fitted by using only one adjustable parameter. In addition to the fitted data also simulated data were generated and utilized in explaining the effect of the eluent composition and of the resin characteristics on the carbohydrate separation.

The Influence of Process Conditions on the Deresination Efficiency in Mechanical Pulp Washing

The aim of this thesis was to produce information for the estimation of the flow balance of wood resin in mechanical pulping and to demonstrate the possibilities for improving the efficiency of deresination in practice. It was observed that chemical changes in wood resin take place only during peroxide bleaching, a significant amount of water dispersed wood resin is retained in the pulp mat during dewatering and the amount of wood resin in the solid phase of the process filtrates is very small. On the basis of this information there exist three parameters related to behaviour of wood resin that determine the flow balance in the process: 1. The liberation of wood resin to the pulp water phase 2. Theretention of water dispersed wood resin in dewatering 3. The proportion of wood resin degraded in the peroxide bleaching The effect of different factors on these parameters was evaluated with the help of laboratory studies and a literature survey. Also, information related to the values of these parameters in existing processes was obtained in mill measurements. With the help of this information, it was possible to evaluate the deresination efficiency and the effect of different factors on this efficiency in a pulping plant that produced low-freeness mechanical pulp. This evaluation showed that the wood resin content of mechanical pulp can be significantly decreased if there exists, in the process, a peroxide bleaching and subsequent washing stage. In the case of an optimal process configuration, as high as a 85 percent deresination efficiency seems to be possible with a water usage level of 8 m3/o.d.t.