Kullan talteenotto takaisinuuttoliuoksista

Työssä tutkittiin kirjallisuuden ja laboratoriomittausten avulla vaihtoehtoja kullan pelkistämiseen ja talteenottoon kultauuton takaisinuuttoliuoksista. Tavoitteena oli löytää menetelmä, jolla saadaan puhdasta kiinteää lopputuotetta ilman kullan häviöitä. Käytettyjä pelkistimiä olivat D-(+)-glukoosi, natriumboorihydridi, L-askorbiinihappo, D-(-)-isoaskorbiinihappo ja aktiivihiili. Laboratoriokokeiden perusteella D-(-)-isoaskorbiinihappo sekä aktiivihiili olivat sopivimmat pelkistimet kokeissa käytetylle kultaliuokselle. Isoaskorbiinihapolla suoritettiin panoskokeita lasireaktorissa eri alku-pH:ssa sekä erilaisilla pelkistimen ja kullan moolisuhteilla. Tulosten perusteella havaittiin pH:n ja pelkistimen ylimäärän vaikuttavan merkittävästi lopputuotteen puhtauteen. Myös redox-potentiaalia säätämällä ja happopesulla pelkistyksen jälkeen voidaan vaikuttaa lopputuotteen puhtauteen. Aktiivihiilellä suoritettiin panoskokeita adsorptiotasapainojen (latausisotermi) ja kinetiikan tutkimiseksi. Hiileen on mahdollista saada kultaa 383 mg/g kuivaa hiiltä. Suurempi lataus voitaisiin saavuttaa käyttämällä hiiltä, jolla on pienempi partikkelikoko. Kolonnikokeita tehtiin eri virtausnopeuksilla. Kolonnikokeissa kullan dynaaminen adsorptiokapasiteetti hiileen odotetusti kasvoi virtausnopeuden laskiessa. Pienin käytetty virtausnopeus oli 2,40 BV/h, jolloin kapasiteetti oli 75,4 mg/g kuivaa hiiltä (c (Au feed) = 129 mg/L). Kullasta voidaan poistaa myös kolonnipelkistyksen jälkeen epäpuhtauksia happopesulla. Isoaskorbiinihapolla pelkistyksen kinetiikka on nopea ja sillä saatiin pelkistettyä puhdasta lopputuotetta. Sekä isoaskorbiinihappo, että aktiivihiili ovat potentiaalisia menetelmiä kullan talteenottoon.

Drug loading of mesoporous silicon particles

Porous silicon (PSi) is a promising material to be utilized in drug delivery formulations. The release rate of the drug compound can be controlled by changing the pore properties and surface chemistry of PSi. The loading of a poorly soluble drug into mesoporous silicon particles enhances its dissolution in the body. The drug loading is based on adsorption. The attainable maximum loaded amount depends on the properties of the drug compound and the PSi material, and on the process conditions. The loading solvent also essentially affects the adsorption process. The loading of indomethacin into PSi particles with varying surface modification was studied. Solvent mixtures were applied in the loading, and the loaded samples were analyzed with thermal analysis methods. The best degree of loading was obtained using a mixture of dichloromethane and methanol. The drug loads varied from 7.7 w-% to 26.8 w-%. A disturbing factor in the loading experiments was the tendency of indomethacin to form solvates with the solvents applied. In addition, the physical form and stability of indomethacin loaded in PSi and silica particles were studied using Raman spectroscopy. In the case of silica, the presence of crystalline drug as well as the polymorph form can be detected, but the method proved to be not applicable for PSi particles.

The influence ofvariable amplitude loading on the fatigue strength of rhs corners

Rectangular hollow section (RHS) members are components widely used in engineering applications because of their good-looking, good properties in engineering areas and inexpensive cost comparing to members with other sections. The increasing use of RHS in load bearing structures makes it necessary to analyze the fatigue behavior of the RHS members. In this thesis, concentration will be given to the fatigue behavior of the RHS members under variable amplitude pure torsional loading. For the RHS members, failure will normally occur in the corner region if the welded regions are under full penetration. This is because of the complicated stress components' distributions at the RHScorners, where all of three fracture mechanics modes will happen. Mode I is mainly caused by the residual stresses that caused by the manufacturing process. Modes II and III are caused by the applied torsional loading. Stress based Findleymodel is also used to analyze the stress components. Constant amplitude fatigue tests have been done as well as variable amplitude fatigue tests. The specimens under variable amplitude loading gave longer fatigue lives than those under constant amplitude loading. Results from tests show an S-N curvewith slope around 5.

Fatigue Analysis of Welded Cruciform Joints with Cold Laps

Työssä on tutkittu vetojännityskuormituksen alaisena olevien hitsattujen kuormaa kantamattomien X-liitosten hitsin paikallisen geometrian variaation vaikutusta väsymislujuuteen. Muuttujina olivat reunan pyöristyssäde, kylmäjuoksun suuruus ja kylkikulma. Geometristen muuttujien parametrinen riippuvuussuhde on analysoitu usealla elementtimallilla. Väsymistarkastelu on suoritettu käyttämällä lineaaris-elastista murtumismekaniikkaa (LEFM) tasovenymätilassa ja materiaalina terästä. Särönkasvun suunnan ennustamisessaon käytetty maksimipääjännityskriteeriä sekä jännitysintensiteettikertoimet on määritetty J-integraalilla. Särön ydintymisvaihetta ei ole otettu huomioon. Rakenteen on oletettu olevan hitsatussa tilassa ja jännitysheilahdus on kokonaan tehollinen. Särön kasvunopeuden ennustamiseen on käytetty Paris'n lakia. Väsymislujuustulokset on esitetty karakteristisina väsymisluokkina (FAT) ja sovitettu parametriseksi yhtälöksi. Lopuksi väsymisanalyysin ennustamia tuloksia on verrattu saatavilla oleviin väsytystestituloksiin.

Jätevedenpuhdistamon toiminnan optimointi

Schauman Wood Oy Pelloksen tehtaat on Euroopan suurin havuvanerin valmistaja. Tehtailla tukkien haudonnassa ja kuorien kuivaamisessa syntyvät jätevedet sekä sosiaalijätevedet puhdistetaan omassa biologisessa puhdistamossa. Puhdistamo rakennettiin alun perin aktiivilietelaitokseksi ja muutettiin kuormituksen kasvaessa vuonna 2002 kantoaineprosessiksi. Puhdistamolle laskettiin ensin optimaalinen kuormitus, jonka perusteella kuormitusta ryhdyttiin nostamaan. Tavoitteena oli saavuttaa virtaaman nostolla ja ajomallien muutoksilla tilavuuskuorma 1-3 kgBOD/m3•d. Kun tulovirtaamaa oli saatu nostettua riittävästi, tehtiin laskeutuskokeita laskeutuskemikaalin optimimäärän selvittämiseksi. Koeajojakson lopuksi pidettiin kolmen viikon tehotarkkailujakso, jolloin kokeiltiin puhdistamon ajoa erilaisilla kemikaalimäärillä. Näin saatiin selville tasemielessä tietyn puumäärän aiheuttama kuormitus puhdistamolle. Jätevedenpuhdistamon tulovirtaama saatiin nostettua tasolle 300- 350 m³/d, jolloin tilaavuuskuormaksi tuli 1,68 kgBOD/m3•d. Kolmen viikon tehotarkkailujakson aikana saatiin selvitettyä optimikemikaaliannostus sekä laskettua kolmesta eri vaihtoehdosta taloudellisesti kannattavin ajomalli. Puhdistusreduktioiden, puhdistamon toimivuuden ja taloudellisuuden kannalta paras vaihtoehto oli laskeutuskemikaalin ja polymeerin yhteiskäyttö.

Haja-asutusalueiden jätevesien käsittelyn tulevaisuus

Tässä työssä tarkastellaan haja-asutusalueilla käytössä olevia kiinteistökohtaisia jäteveden käsittelymenetelmiä. Koelaitteistona oli biologinen pienpuhdistamo, jonka toimintaa tutkittiin tavanomaisessa kotitalouskäytössä. Tarkoituksena oli selvittää jäteveden biologisen suodatuksen soveltuvuutta haja-asutuksen jätevesien käsittelyyn. Kirjallisuusosiossa käsitellään haja-asutuksen jätevesien aiheuttamia ympäristövaikutuksia, ympäristölainsäädäntöä ja yleisesti käytössä olevia erilaisia jäteveden käsittelymenetelmiä, sekä vaihtoehtoisia käymäläratkaisuja. Ennen kokeellisen osuuden alkua asennettiin pienpuhdistamo oheislaitteineen omakotitalon viemärijärjestelmään. Tämän jälkeen päästiin tutkimaan puhdistamon puhdistustehokkuutta ja ympäristökuormitusta lähtevästä jätevedestä keräilynäyttein. Puhdistamolta lähtevän jäteveden kuormitusarvoja verrattiin Ympäristöministeriössä suunnitteilla oleviin enimmäisrajoihin: BOD7 5 g/(d,as), kokonaisfosfori 0,33 g/(d,as) ja kokonaistyppi 8,4 g/(d,as). Mitatut BOD7- ja kokonaistyppikuormitukset alittivat raja-arvot kerran. Muilla mittauskerroilla kuormitus oli enimmäisrajoja suurempi. Kokonaisfosforikuormitus oli kaikilla mittauskerroilla moninkertainen enimmäisrajaan verrattuna. Puhdistamon todellinen BOD7-reduktio oli noin 60 %. Kokonaisfosforin ja kokonaistypen reduktiot vaihtelivat paljon ollen kokonaisfosforilla korkeimmillaan 12 % ja kokonaistypellä 29 %.

On the Application of Beam on Elastic Foundation Theory to the Analysis of Stiffened Plate Strips

The main objective of this thesis is to show that plate strips subjected to transverse line loads can be analysed by using the beam on elastic foundation (BEF) approach. It is shown that the elastic behaviour of both the centre line section of a semi infinite plate supported along two edges, and the free edge of a cantilever plate strip can be accurately predicted by calculations based on the two parameter BEF theory. The transverse bending stiffness of the plate strip forms the foundation. The foundation modulus is shown, mathematically and physically, to be the zero order term of the fourth order differential equation governing the behaviour of BEF, whereas the torsion rigidity of the plate acts like pre tension in the second order term. Direct equivalence is obtained for harmonic line loading by comparing the differential equations of Levy's method (a simply supported plate) with the BEF method. By equating the second and zero order terms of the semi infinite BEF model for each harmonic component, two parameters are obtained for a simply supported plate of width B: the characteristic length, 1/ λ, and the normalized sum, n, being the effect of axial loading and stiffening resulting from the torsion stiffness, nlin. This procedure gives the following result for the first mode when a uniaxial stress field was assumed (ν = 0): 1/λ = √2B/π and nlin = 1. For constant line loading, which is the superimposition of harmonic components, slightly differing foundation parameters are obtained when the maximum deflection and bending moment values of the theoretical plate, with v = 0, and BEF analysis solutions are equated: 1 /λ= 1.47B/π and nlin. = 0.59 for a simply supported plate; and 1/λ = 0.99B/π and nlin = 0.25 for a fixed plate. The BEF parameters of the plate strip with a free edge are determined based solely on finite element analysis (FEA) results: 1/λ = 1.29B/π and nlin. = 0.65, where B is the double width of the cantilever plate strip. The stress biaxial, v > 0, is shown not to affect the values of the BEF parameters significantly the result of the geometric nonlinearity caused by in plane, axial and biaxial loading is studied theoretically by comparing the differential equations of Levy's method with the BEF approach. The BEF model is generalised to take into account the elastic rotation stiffness of the longitudinal edges. Finally, formulae are presented that take into account the effect of Poisson's ratio, and geometric non linearity, on bending behaviour resulting from axial and transverse inplane loading. It is also shown that the BEF parameters of the semi infinite model are valid for linear elastic analysis of a plate strip of finite length. The BEF model was verified by applying it to the analysis of bending stresses caused by misalignments in a laboratory test panel. In summary, it can be concluded that the advantages of the BEF theory are that it is a simple tool, and that it is accurate enough for specific stress analysis of semi infinite and finite plate bending problems.

Nosturin kuormauselimen liitynnän suunnittelu

Paperiteollisuuden prosessituotteista paperia varastoidaan erikokoisina rullina esim. pystyrullavarastoihin. Tämän diplomityön tavoitteena oli kehittää Konecranesin prosessinosturille liityntä paperirullia käsittelevän kuormauselimen ja nosturin välille. Tavoitteena oli löytää kiinnitysmenetelmä, joka mahdollistaa nosturien joustavan käytön mahdollisimman pienin muutoksin itse nosturin standardoituun rakenteeseen. Pääasiallisena syventymisen kohteena oli alipaineella paperirullia nostettavan kuormauselimen liityntä. Liitynnän on kyettävä joustamaan ja vaimentamaan paperirullia nostavaan kuormauselimeen nosturin liikkeelle lähdöstä ja pysähtymisestä syntyvät herätteet ja voimat. Nosturin liikenopeus on kyettävä pitämään mahdollisimman suurena lyhyen rullienkäsittelyajan saavuttamiseksi. Liitynnältä vaaditaan kykyä ottaa kuormauselin vastaan mahdollisimman suurella nostonopeudella. Lisäksi kuorman ja kuormauselimen oskillaatio on vaimennettava mahdollisimman nopeasti samalla rajoittaen heilunnasta aiheutuvaa maksimi siirtymää. Liitynnän suunnittelu pohjautuu nosturin, kuormauselimen ja paperirullan muodostaman systeemin teoreettiseen tarkasteluun. Systeemistä laadittiin dynaaminen malli, jonka avulla tutkittiin oskillaation ja syntyvien kiihtyvyyksien suuruutta. Näiden teoriaan perustuvien tuloksien pohjalta suunniteltiin vaimennukseen tarvittavat vaimennuselementit ja liitynnän rakenne. Suunnittelutyön tuloksena saatiin liitynnälle alustava rakenne, joka mahdollistaa käytettävien vaimennuselementtien vaihtamisen ja siten tehokkaan heilunnan vaimmennuksen. Suunnittelutyön lähtökohtana oleva teoreettinen tarkastelu vaatii tuekseen esim. prototyypin kokeellisten tulosten saamiseksi ennen lopullisen tuotteen valmistamista. Suunnitteluprosessissa noudatettiin järjestelmällisen tuotesuunnittelun vaiheita ja menetelmiä.

Recovery and refining of manganese as by-product from hydrometallurgical processes

The consumption of manganese is increasing, but huge amounts of manganese still end up in waste in hydrometallurgical processes. The recovery of manganese from multi-metal solutions at low concentrations may not be economical. In addition, poor iron control typically prevents the production of high purity manganese. Separation of iron from manganese can be done with chemical precipitation or solvent extraction methods. Combined carbonate precipitation with air oxidation is a feasible method to separate iron and manganese due to the fast kinetics, good controllability and economical reagents. In addition the leaching of manganese carbonate is easier and less acid consuming than that of hydroxide or sulfide precipitates. Selective iron removal with great efficiency from MnSO4 solution is achieved by combined oxygen or air oxidation and CaCO3 precipitation at pH > 5.8 and at a redox potential of > 200 mV. In order to avoid gypsum formation, soda ash should be used instead of limestone. In such case, however, extra attention needs to be paid on the reagents mole ratios in order to avoid manganese coprecipitation. After iron removal, pure MnSO4 solution was obtained by solvent extraction using organophosphorus reagents, di-(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4- trimethylpentyl)phosphinic acid (CYANEX 272). The Mn/Ca and Mn/Mg selectivities can be increased by decreasing the temperature from the commonly used temperatures (40 –60oC) to 5oC. The extraction order of D2EHPA (Ca before Mn) at low temperature remains unchanged but the lowering of temperature causes an increase in viscosity and slower phase separation. Of these regents, CYANEX 272 is selective for Mn over Ca and, therefore, it would be the better choice if there is Ca present in solution. A three-stage Mn extraction followed by a two-stage scrubbing and two-stage sulfuric acid stripping is an effective method of producing a very pure MnSO4 intermediate solution for further processing. From the intermediate MnSO4 some special Mn- products for ion exchange applications were synthesized and studied. Three types of octahedrally coordinated manganese oxide materials as an alternative final product for manganese were chosen for synthesis: layer structured Nabirnessite, tunnel structured Mg-todorokite and K-kryptomelane. As an alternative source of pure MnSO4 intermediate, kryptomelane was synthesized by using a synthetic hydrometallurgical tailings. The results show that the studied OMS materials adsorb selectively Cu, Ni, Cd and K in the presence of Ca and Mg. It was also found that the exchange rates were reasonably high due to the small particle dimensions. Materials are stable in the studied conditions and their maximum Cu uptake capacity was 1.3 mmol/g. Competitive uptake of metals and acid was studied using equilibrium, batch kinetic and fixed-bed measurements. The experimental data was correlated with a dynamic model, which also accounts for the dissolution of the framework manganese. Manganese oxide micro-crystals were also bound onto silica to prepare a composite material having a particle size large enough to be used in column separation experiments. The MnOx/SiO2 ratio was found to affect significantly the properties of the composite. The higher the ratio, the lower is the specific surface area, the pore volume and the pore size. On the other hand, higher amount of silica binder gives composites better mechanical properties. Birnesite and todorokite can be aggregated successfully with colloidal silica at pH 4 and with MnO2/SiO2 weight ratio of 0.7. The best gelation and drying temperature was 110oC and sufficiently strong composites were obtained by additional heat-treatment at 250oC for 2 h. The results show that silica–supported MnO2 materials can be utilized to separate copper from nickel and cadmium. The behavior of the composites can be explained reasonably well with the presented model and the parameters estimated from the data of the unsupported oxides. The metal uptake capacities of the prepared materials were quite small. For example, the final copper loading was 0.14 mmol/gMnO2. According to the results the special MnO2 materials are potential for a specific environmental application to uptake harmful metal ions.

Energy Efficiency of a Diesel-Electric MobileWorking Machine

The power demand of many mobile working machines such as mine loaders, straddle carriers and harvesters varies significantly during operation, and typically, the average power demand of a working machine is considerably lower than the demand for maximum power. Consequently, for most of the time, the diesel engine of a working machine operates at a poor efficiency far from its optimum efficiency range. However, the energy efficiency of dieseldriven working machines can be improved by electric hybridization. This way, the diesel engine can be dimensioned to operate within its optimum efficiency range, and the electric drive with its energy storages responds to changes in machine loading. A hybrid working machine can be implemented in many ways either as a parallel hybrid, a series hybrid or a combination of these two. The energy efficiency of hybrid working machines can be further enhanced by energy recovery and reuse. This doctoral thesis introduces the component models required in the simulation model of a working machine. Component efficiency maps are applied to the modelling; the efficiency maps for electrical machines are determined analytically in the whole torque–rotational speed plane based on the electricalmachine parameters. Furthermore, the thesis provides simulation models for parallel, series and parallel-series hybrid working machines. With these simulation models, the energy consumption of the working machine can be analysed. In addition, the hybridization process is introduced and described. The thesis provides a case example of the hybridization and dimensioning process of a working machine, starting from the work cycle of the machine. The selection and dimensioning of the hybrid system have a significant impact on the energy consumption of a hybrid working machine. The thesis compares the energy consumption of a working machine implemented by three different hybrid systems (parallel, series and parallel-series) and with different component dimensions. The payback time of a hybrid working machine and the energy storage lifetime are also estimated in the study.

Methyl and ethyl chloride synthesis in microreactors

Methyl chloride is an important chemical intermediate with a variety of applications. It is produced today in large units and shipped to the endusers. Most of the derived products are harmless, as silicones, butyl rubber and methyl cellulose. However, methyl chloride is highly toxic and flammable. On-site production in the required quantities is desirable to reduce the risks involved in transportation and storage. Ethyl chloride is a smaller-scale chemical intermediate that is mainly used in the production of cellulose derivatives. Thus, the combination of onsite production of methyl and ethyl chloride is attractive for the cellulose processing industry, e.g. current and future biorefineries. Both alkyl chlorides can be produced by hydrochlorination of the corresponding alcohol, ethanol or methanol. Microreactors are attractive for the on-site production as the reactions are very fast and involve toxic chemicals. In microreactors, the diffusion limitations can be suppressed and the process safety can be improved. The modular setup of microreactors is flexible to adjust the production capacity as needed. Although methyl and ethyl chloride are important chemical intermediates, the literature available on potential catalysts and reaction kinetics is limited. Thus the thesis includes an extensive catalyst screening and characterization, along with kinetic studies and engineering the hydrochlorination process in microreactors. A range of zeolite and alumina based catalysts, neat and impregnated with ZnCl2, were screened for the methanol hydrochlorination. The influence of zinc loading, support, zinc precursor and pH was investigated. The catalysts were characterized with FTIR, TEM, XPS, nitrogen physisorption, XRD and EDX to identify the relationship between the catalyst characteristics and the activity and selectivity in the methyl chloride synthesis. The acidic properties of the catalyst were strongly influenced upon the ZnCl2 modification. In both cases, alumina and zeolite supports, zinc reacted to a certain amount with specific surface sites, which resulted in a decrease of strong and medium Brønsted and Lewis acid sites and the formation of zinc-based weak Lewis acid sites. The latter are highly active and selective in methanol hydrochlorination. Along with the molecular zinc sites, bulk zinc species are present on the support material. Zinc modified zeolite catalysts exhibited the highest activity also at low temperatures (ca 200 °C), however, showing deactivation with time-onstream. Zn/H-ZSM-5 zeolite catalysts had a higher stability than ZnCl2 modified H-Beta and they could be regenerated by burning the coke in air at 400 °C. Neat alumina and zinc modified alumina catalysts were active and selective at 300 °C and higher temperatures. However, zeolite catalysts can be suitable for methyl chloride synthesis at lower temperatures, i.e. 200 °C. Neat γ-alumina was found to be the most stable catalyst when coated in a microreactor channel and it was thus used as the catalyst for systematic kinetic studies in the microreactor. A binder-free and reproducible catalyst coating technique was developed. The uniformity, thickness and stability of the coatings were extensively characterized by SEM, confocal microscopy and EDX analysis. A stable coating could be obtained by thermally pretreating the microreactor platelets and ball milling the alumina to obtain a small particle size. Slurry aging and slow drying improved the coating uniformity. Methyl chloride synthesis from methanol and hydrochloric acid was performed in an alumina-coated microreactor. Conversions from 4% to 83% were achieved in the investigated temperature range of 280-340 °C. This demonstrated that the reaction is fast enough to be successfully performed in a microreactor system. The performance of the microreactor was compared with a tubular fixed bed reactor. The results obtained with both reactors were comparable, but the microreactor allows a rapid catalytic screening with low consumption of chemicals. As a complete conversion of methanol could not be reached in a single microreactor, a second microreactor was coupled in series. A maximum conversion of 97.6 % and a selectivity of 98.8 % were reached at 340°C, which is close to the calculated values at a thermodynamic equilibrium. A kinetic model based on kinetic experiments and thermodynamic calculations was developed. The model was based on a Langmuir Hinshelwood-type mechanism and a plug flow model for the microreactor. The influence of the reactant adsorption on the catalyst surface was investigated by performing transient experiments and comparing different kinetic models. The obtained activation energy for methyl chloride was ca. two fold higher than the previously published, indicating diffusion limitations in the previous studies. A detailed modeling of the diffusion in the porous catalyst layer revealed that severe diffusion limitations occur starting from catalyst coating thicknesses of 50 μm. At a catalyst coating thickness of ca 15 μm as in the microreactor, the conditions of intrinsic kinetics prevail. Ethanol hydrochlorination was performed successfully in the microreactor system. The reaction temperature was 240-340°C. An almost complete conversion of ethanol was achieved at 340°C. The product distribution was broader than for methanol hydrochlorination. Ethylene, diethyl ether and acetaldehyde were detected as by-products, ethylene being the most dominant by-product. A kinetic model including a thorough thermodynamic analysis was developed and the influence of adsorbed HCl on the reaction rate of ethanol dehydration reactions was demonstrated. The separation of methyl chloride using condensers was investigated. The proposed microreactor-condenser concept enables the production of methyl chloride with a high purity of 99%.

Intelligent mapping of stresses in a hydraulic crane

Continuous loading and unloading can cause breakdown of cranes. In seeking solution to this problem, the use of an intelligent control system for improving the fatigue life of cranes in the control of mechatronics has been under study since 1994. This research focuses on the use of neural networks as possibilities of developing algorithm to map stresses on a crane. The intelligent algorithm was designed to be a part of the system of a crane, the design process started with solid works, ANSYS and co-simulation using MSc Adams software which was incorporated in MATLAB-Simulink and finally MATLAB neural network (NN) for the optimization process. The flexibility of the boom accounted for the accuracy of the maximum stress results in the ADAMS model. The flexibility created in ANSYS produced more accurate results compared to the flexibility model in ADAMS/View using discrete link. The compatibility between.ADAMS and ANSYS softwares was paramount in the efficiency and the accuracy of the results. Von Mises stresses analysis was more suitable for this thesis work because the hydraulic boom was made from construction steel FE-510 of steel grade S355 with yield strength of 355MPa. Von Mises theory was good for further analysis due to ductility of the material and the repeated tensile and shear loading. Neural network predictions for the maximum stresses were then compared with the co-simulation results for accuracy, and the comparison showed that the results obtained from neural network model were sufficiently accurate in predicting the maximum stresses on the boom than co-simulation.

Study on Customer Perceived Value of Container Loading Equipment

The goal of the thesis was to gain understanding of organizational buying behavior and its effect from the selling perspective and to generate base for verifying customer value propositions for Actiw Oy. The first objective was to discover the current buying decision criteria of current customers to understand the buying motives which had led to the investment initially. Second objective was to understand how the buying decision criteria and customer experiences can be turned into customer value propositions. Research was done with 16 customer interviews, which were focused on obtaining the information on the buying center and the value of the solution. Thesis goes through the main theories of OBB and the theory behind customer value management. Based on customer interviews, the currently used customer value propositions were tested and categorized into points-of-parities and points-ofdifferences. The interviews confirmed customer behavior in new task and modified rebuy situations and also gave confirmation to the internally done customer value propositions. Main finding of the study was, that as the value propositions are possible to present more specifically to each new case instead of using all benefits at the same time.

Recovery and purification of anthocyanins from purple-blue potato

The aim of this work was to study techniques to extract and purify of anthocyanins from purple-blue potato. This topic was determined as a master’s thesis and it was done in collaboration with the Food Chemistry and Food Development Department of University of Turku and Department of Chemical and Process Engineering at Lappeenranta University of Technology. At first, purple-blue potatoes were pretreated in four types of boiled, raw, freeze-dried and dried boiled potato for extraction. They were mixed with aqueous acidified ethanol (ethanol:water:acetic acid 40%:53%:7% v/v) for conventional extraction. Boiled potato was selected as a best pretreated potato. Different ethanol concentration and extraction time were examined and the mixture of 80% in 24 h resulted in maximum anthocyanin content (132.23 mg/L). As conventional extraction method of anthocyanins was non-selective, some of impurities such as free sugars might accelerate anthocyanin degradation. Therefore, to obtain anthocyanins in purified form, adsorption as a promising selective method was used to recovery and isolate anthocyanins. It was carried out with six adsorbents. Among those, Amberlite XAD-7HP, a nonionic acrylic ester adsorbent, was found to have the best performance. In an adsorption column, flow rate of 3 mL/min was selected as the loading flow rate among four tested flow rates. Eluent volume and flow rate were 3 BV of aqueous acidified ethanol (75%, v/v) and 1 mL/min for desorption. The quantification of the total anthocyanin contents was performed by pH-differential method using UV-vis spectrophotometer. The resulting anthocyanin solution after purification was almost free from free sugars which were the major cause for degradation of anthocyanins. The average anthocyanin concentration in the purified and concentrated sample was obtained 1752.89 mg/L.

Effect of loading type on the fatigue strength of symmetric and asymmetric welded joints made of ultra high strength steel

In this study, finite element analyses and experimental tests are carried out in order to investigate the effect of loading type and symmetry on the fatigue strength of three different non-load carrying welded joints. The current codes and recommendations do not give explicit instructions how to consider degree of bending in loading and the effect of symmetry in the fatigue assessment of welded joints. The fatigue assessment is done by using effective notch stress method and linear elastic fracture mechanics. Transverse attachment and cover plate joints are analyzed by using 2D plane strain element models in FEMAP/NxNastran and Franc2D software and longitudinal gusset case is analyzed by using solid element models in Abaqus and Abaqus/XFEM software. By means of the evaluated effective notch stress range and stress intensity factor range, the nominal fatigue strength is assessed. Experimental tests consist of the fatigue tests of transverse attachment joints with total amount of 12 specimens. In the tests, the effect of both loading type and symmetry on the fatigue strength is studied. Finite element analyses showed that the fatigue strength of asymmetric joint is higher in tensile loading and the fatigue strength of symmetric joint is higher in bending loading in terms of nominal and hot spot stress methods. Linear elastic fracture mechanics indicated that bending reduces stress intensity factors when the crack size is relatively large since the normal stress decreases at the crack tip due to the stress gradient. Under tensile loading, experimental tests corresponded with finite element analyzes. Still, the fatigue tested joints subjected to bending showed the bending increased the fatigue strength of non-load carrying welded joints and the fatigue test results did not fully agree with the fatigue assessment. According to the results, it can be concluded that in tensile loading, the symmetry of joint distinctly affects on the fatigue strength. The fatigue life assessment of bending loaded joints is challenging since it depends on whether the crack initiation or propagation is predominant.