Paperin pintaenergian vaikutus painovärin tarpeeseen

Työn tavoitteena oli selvittää pintaenergian vaikutus painovärin tarpeeseen IGT-laboratoriopainokoneella. Lisäksi selvitettiin onko karheudella vaikutusta kontaktikulmamittaukseen. Työ koostui kirjallisuusosasta ja kokeellisesta osasta. Kirjallisuusosassa tarkasteltiin aihepiiriä koskevia teorioita ja aiempia tutkimuksia. Kokeellisessa osassa valmistettiin laboratoriomittakaavassa pintaenergialtaan ja karheudeltaan erilaisia papereita. Pintaenergiaa muuteltiin kolmen erilaisen massaliiman ja kahden erilaisen pintaliiman avulla. Paperin karheutta säädettiin kalanteroinnilla. Papereista mitattiin pintaominaisuuksia, nesteen ja paperin välinen kontaktikulma, sekä suoritettiin painatuskokeita. Pintaenergia laskettiin kirjallisuudesta löytyneiden teorioiden perusteella ja näiden pintaenergian laskemismenetelmien käyttökelpoisuutta pintaenergian määrittämiseen selvitettiin. Lisäksi tutkittiin pintaenergian vaikutusta painovärin tarpeeseen. Tämä työ selvästi osoittaa, että yhden, kahden ja kolmen komponentin menetelmällä ja nesteitä vaihtelemalla saadaan erilaisia pintaenergian tuloksia. Pintaenergian määrittämiseen vaikuttaa myös kontaktikulmamittausten hankaluus ja kontaktikulman suuri vaihtelu, joka vaikuttaa koko mittaussarjan luotettavuustarkasteluun. Lisäksi paperin karheudella ja huokoisuudella oli merkitystä kontaktikulmamittaukseen.

Verenpaineen mittaamisen opettaminen sairaanhoitaja- ja terveydenhoitajaopiskelijoille

Teaching the measurement of blood pressure for both nursing and public health nursing students The purpose of this two-phase study was to develop the teaching of blood pressure measurement within the nursing degree programmes of the Universities of Applied Sciences. The first survey phase described what and how blood pressure measurement was taught within nursing degree programmes. The second intervention phase (2004-2005) evaluated first academic year nursing and public health nursing students’ knowledge and skills results for blood pressure measurement. Additionally, the effect on the Taitoviikko experimental group students’ blood pressure measurement knowledge and skills level. A further objective was to construct models for an instrument (RRmittTest) to evaluate nursing students measurement of blood pressure (2003-2009). The research data for the survey phase were collected from teachers (total sampling, N=107, response rate 77%) using a specially developed RRmittopetus-questionnaire. Quasi-experimental study data on the RRmittTest-instrument was collected from students (purposive sampling, experimental group, n=29, control group, n=44). The RRmittTest consisted of a test of knowledge (Tietotesti) and simulation-based test (TaitoSimkäsi and Taitovideo) of skills. Measurements were made immediately after the teaching and in clinical practice. Statistical methods were used to analyse the results and responses to open-ended questions were organised and classified. Due to the small amount of materials involved and the results of distribution tests of the variables, non-parametric analytic methods were mainly used. Experimental group and control group similar knowledge and skills teaching was based on the results of the national survey phase (RRmittopetus) questionnaire results. Experimental group teaching includes the supervised Taitoviikko teaching method. During Taitoviikko students studied blood pressure measurement at the municipal hospital in a real nursing environment, guided by a teacher and a clinical nursing professional. In order to evaluate both learning and teaching the processes and components of blood pressure measurement were clearly defined as follows: the reliability of measurement instruments, activities preceding blood pressure measurement, technical execution of the measurement, recording, lifestyle guidance and measurement at home (self-monitoring). According to the survey study, blood pressure measurement is most often taught at Universities of Applied Sciences, separately, as knowledge (teaching of theory, 2 hours) and skills (classroom practice, 4 hours). The teaching was implemented largely in a classroom and was based mainly on a textbook. In the intervention phase the students had good knowledge of blood pressure measurement. However, their blood pressure measurement skills were deficient and the control group students, in particular, were highly deficient. Following in clinical practice the experimental group and control group students’ blood pressure measurement recording knowledge improve and experimental groups declined lifestyle guidance. Skills did not improve within any of the components analysed. The control groups` skills on the whole, declined statistically.There was a significant decline amongst the experimental group although only in one component measured. The results describe the learning results for first academic year students and no parallel conclusions should be drawn when considering any learning results for graduating students. The results support the use and further development of the Taitoviiko teaching method. The RRmittTest developed for the study should be assessed and the results seen from a negative perspective. This evaluation tool needs to be developed and retested.

Adsorption of hydrogen sulfide by modified cellulose nano/microcrystals

Hydrogen sulfide is toxic and hazardous pollutant. It has been under great interest for past few years because of all the time tighten environmental regulations and increased interest of mining. Hydrogen sulfide gas originates from mining and wastewater treatment systems have caused death in two cases. It also causes acid rains and corrosion for wastewater pipelines. The aim of this master thesis was to study if chemically modified cellulose nanocrystals could be used as adsorbents to purify hydrogen sulfide out from water and what are the adsorption capacities of these adsorbents. The effects of pH and backgrounds on adsorption capacities of different adsorbents are tested. In theoretical section hydrogen sulfide, its properties and different purification methods are presented. Also analytical detection methods for hydrogen sulfide are presented. Cellulose nano/microcrystals, properties, application and different modification methods are discussed and finally theory of adsorption and modeling of adsorption is shortly discussed. In experimental section different cellulose nanocrystals based adsorbents are prepared and tested at different hydrogen sulfide concentrations and in different conditions. Result of experimental section was that the highest adsorption capacity at one component adsorption had wet MFC/CaCO3. At different pH the adsorption capacities of adsorbents changed quite dramatically. Also change of hydrogen sulfide solution background did have effect on adsorption capacities. Although, when tested adsorbents’ adsorption capacities are compared to those find in literatures, it seems that more development of MFC based adsorbents is needed.

Permuurahaishapon valmistaminen mikroreaktorissa

Kandidaatintyön teoriaosassa perehdytään mikroreaktoreihin sekä niiden etuihin ja haasteisiin. Lisäksi esitellään lyhyesti, kuinka sekoitus näissä reaktoreissa voidaan järjestää erilaisten sekoituselementtien avulla sekä uusien ainetta lisäävien valmistusmenetelmien tarjoamat mahdollisuudet reaktorien valmistukselle. Mikroreaktorien edut liittyvät pääasiassa prosessin helpompaan hallittavuuteen, mikä johtaa mm. turvallisuuden lisääntymiseen ja energiasäästöihin. Lisäksi esitellään kokeellisessa osassa lähtöaineina käytettävät vetyperoksidi ja muurahaishappo, sekä tuotteena syntyvä permuurahaishappo ja sen käyttökohteita. Permuurahaishappoa käytetään mm. desinfiointiaineiden yhtenä komponenttina. Sitä voidaan käyttää myös paperikoneen vesikierron bakteerien tappamiseen. Epästabiiliutensa vuoksi permuurahaishappo voi räjähtää jopa huoneenlämmössä, mikä aiheuttaa merkittävän riskin sen varastoinnille ja kuljetukselle. Tästä syystä työssä tutkittu menetelmä permuurahaishapon valmistamiseksi mikroreaktorissa tarjoaa hyvän vaihtoehdon permuurahaishapon tuottamiseksi suoraan tarpeeseen. Kokeellisessa osassa permuurahaishappoa valmistettiin muurahaishaposta ja vetyperoksidista käyttäen rikkihappoa katalyyttinä reaktion nopeuttamiseksi. Lämpötilan ja viipymäajan vaikutusta tutkittiin permuurahaishapon muodostumiseen. Molempien nosto vaikutti edullisesti permuurahaishapon saantoon, mutta lämpötilan nosto lisää samalla räjähdysriskiä. Mikroreaktorissa lämpötilan nosto on kuitenkin suhteessa turvallisempaa makroreaktoriin verrattuna.

In For a Penny, In For a Pound: The Management and Preservation of E-Theses in EPrints

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

An EDTA-β-cyclodextrin adsorbent for the adsorption of rare earth elements and its application in preconcentration of ultratrace rare earth elements from seawater

The objectives of this work were synthesizing an EDTA-β-CD adsorbent and investigating its adsorption potential and applications in preconcentration of REEs from aqueous phase. The adsorption capacity of EDTA-β-CD was investigated. The adsorption studies were performed by batch techniques both in one- and multi-component systems. The effects of pH, contact time and initial concentration were evaluated. The analytical detection methods and characterization methods were presented. EDTA-β-CD adsorbent was synthesized successfully with high EDTA coverage. The maximum REEs uptake was 0.310 mmol g-1 for La(III), 0.337 mmol g-1 for Ce(III) and 0.353 mmol g-1 for Eu(III), respectively. The kinetics of REEs onto EDTA-β-CD fitted well to pseudo-second-order model and the adsorption rate was affected by intra-particle diffusion. The experimental data of one component studies fitted to Langmuir isotherm model indicating the homogeneous surface of the adsorbent. The extended Sips model was applicable for the isotherm studies in three-component system. The electrostatic interaction, chelation and complexation were all involved in the adsorption mechanism. The preconcentration of RE ions and regeneration of EDTA-β-CD were successful. Overall, EDTA-β-CD is an effective adsorbent in adsorption and preconcentration of REEs.

Intensification of hemicellulose hot-water extraction from spruce wood by parameter tuning

The growing population on earth along with diminishing fossil deposits and the climate change debate calls out for a better utilization of renewable, bio-based materials. In a biorefinery perspective, the renewable biomass is converted into many different products such as fuels, chemicals, and materials, quite similar to the petroleum refinery industry. Since forests cover about one third of the land surface on earth, ligno-cellulosic biomass is the most abundant renewable resource available. The natural first step in a biorefinery is separation and isolation of the different compounds the biomass is comprised of. The major components in wood are cellulose, hemicellulose, and lignin, all of which can be made into various end-products. Today, focus normally lies on utilizing only one component, e.g., the cellulose in the Kraft pulping process. It would be highly desirable to utilize all the different compounds, both from an economical and environmental point of view. The separation process should therefore be optimized. Hemicelluloses can partly be extracted with hot-water prior to pulping. Depending in the severity of the extraction, the hemicelluloses are degraded to various degrees. In order to be able to choose from a variety of different end-products, the hemicelluloses should be as intact as possible after the extraction. The main focus of this work has been on preserving the hemicellulose molar mass throughout the extraction at a high yield by actively controlling the extraction pH at the high temperatures used. Since it has not been possible to measure pH during an extraction due to the high temperatures, the extraction pH has remained a “black box”. Therefore, a high-temperature in-line pH measuring system was developed, validated, and tested for hot-water wood extractions. One crucial step in the measurements is calibration, therefore extensive efforts was put on developing a reliable calibration procedure. Initial extractions with wood showed that the actual extraction pH was ~0.35 pH units higher than previously believed. The measuring system was also equipped with a controller connected to a pump. With this addition it was possible to control the extraction to any desired pH set point. When the pH dropped below the set point, the controller started pumping in alkali and by that the desired set point was maintained very accurately. Analyses of the extracted hemicelluloses showed that less hemicelluloses were extracted at higher pH but with a higher molar-mass. Monomer formation could, at a certain pH level, be completely inhibited. Increasing the temperature, but maintaining a specific pH set point, would speed up the extraction without degrading the molar-mass of the hemicelluloses and thereby intensifying the extraction. The diffusion of the dissolved hemicelluloses from the wood particle is a major part of the extraction process. Therefore, a particle size study ranging from 0.5 mm wood particles to industrial size wood chips was conducted to investigate the internal mass transfer of the hemicelluloses. Unsurprisingly, it showed that hemicelluloses were extracted faster from smaller wood particles than larger although it did not seem to have a substantial effect on the average molar mass of the extracted hemicelluloses. However, smaller particle sizes require more energy to manufacture and thus increases the economic cost. Since bark comprises 10 – 15 % of a tree, it is important to also consider it in a biorefinery concept. Spruce inner and outer bark was hot-water extracted separately to investigate the possibility to isolate the bark hemicelluloses. It was showed that the bark hemicelluloses comprised mostly of pectic material and differed considerably from the wood hemicelluloses. The bark hemicelluloses, or pectins, could be extracted at lower temperatures than the wood hemicelluloses. A chemical characterization, done separately on inner and outer bark, showed that inner bark contained over 10 % stilbene glucosides that could be extracted already at 100 °C with aqueous acetone.

Colligation and Cross Moment-Based Approaches for Independent Component Analysis

Diplomityössä on käsitelty uudenlaisia menetelmiä riippumattomien komponenttien analyysiin(ICA): Menetelmät perustuvat colligaatioon ja cross-momenttiin. Colligaatio menetelmä perustuu painojen colligaatioon. Menetelmässä on käytetty kahden tyyppisiä todennäköisyysjakaumia yhden sijasta joka perustuu yleiseen itsenäisyyden kriteeriin. Työssä on käytetty colligaatio lähestymistapaa kahdella asymptoottisella esityksellä. Gram-Charlie ja Edgeworth laajennuksia käytetty arvioimaan todennäköisyyksiä näissä menetelmissä. Työssä on myös käytetty cross-momentti menetelmää joka perustuu neljännen asteen cross-momenttiin. Menetelmä on hyvin samankaltainen FastICA algoritmin kanssa. Molempia menetelmiä on tarkasteltu lineaarisella kahden itsenäisen muuttajan sekoituksella. Lähtö signaalit ja sekoitetut matriisit ovattuntemattomia signaali lähteiden määrää lukuunottamatta. Työssä on vertailtu colligaatio menetelmään ja sen modifikaatioita FastICA:an ja JADE:en. Työssä on myös tehty vertailu analyysi suorituskyvyn ja keskusprosessori ajan suhteen cross-momenttiin perustuvien menetelmien, FastICA:n ja JADE:n useiden sekoitettujen parien kanssa.