Polyhedral foams offer large gas-liquid interfacial area associated with a small amount of liquid. Therefore, if a solute adsorbs preferentially at the interface, the concentration of the solute in the foam will be greater than in the solution from which the foam has been generated. This effect provides a simple method of concentrating materials which have a tendency to adsorb on the gas-liquid interface. This is particularly relevant to biomaterials like whole cells, proteins, enzymes etc., which are surface active and are present in low concentrations in the broth. Foam separation has therefore attracted considerable attention, and several reports exist in literature on concentrating cells, proteins and enzymes using foams. Foam separation is based on the difference in surface activity of the components to be separated. A surface active molecule consists of a lyophobic and a lyophilic group. (As water is commonly used as a solvent, the lyophilic and lyophobic groups are called hydrophilic and hydrophobic groups, respectively). When dissolved in a solvent, the presence of lyophobic groups in the interior of the solvent distorts the solvent liquid structure, thereby increasing the free energy of the system.

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While hollow glass microspheres are commonly used in syntactic foam, their abrasive and brittle properties usually result in poor processability and have adverse effects on the foam performance. Therefore, a number of attempts have been made in the industry to replace hollow glass microspheres with polymeric foamed microspheres. Among many choices, expandable thermoplastic (ETP) microspheres filled syntactic foam has shown its high potential to become a novel class of engineering materials, especially for lightweight structural applications. However, conventional processing techniques for syntactic foam usually experience difficulties such as high processing viscosity, low loading of foam fillers, and ineffective microsphere expansion. To address these emerging issues, a microwave expansion process to produce thermoset-matrix syntactic foam containing thermoplastic foam beads was developed in this thesis work. In this process, unexpanded ETP microspheres were directly foamed in uncured thermoset matrix via microwave heating. Expandable polystyrene (EPS) microspheres and epoxy resin were chosen as a model material system. The resin viscosity and specific microwave energy are found to be the two primary control parameters determining the process window. Mechanical characterization showed that the syntactic foam can outweigh neat polymer in lightweight structural applications and was effectively toughened by foamed EPS. Furthermore, the microwave expansion process was found to be capable of molding syntactic foam parts of relatively sophisticated geometry with smooth surfaces. In order to broaden its impact, the microwave expansion process was extended to produce composite EPS foam. This process converts an expandable suspension into a composite foam with a honeycomb-like barrier structure. The suspension viscosity was found to highly influence the foam morphology. Results from mechanical tests showed that the existence of the barrier structure can considerably improve the mechanical performance of the composite foam. Fire-retardation tests demonstrated that the barrier structure can effectively stop the fire path into the foam, suppress toxic smoke generation, and maintain foam structure integrity. A general formulation was developed to model the EPS expansion to optimize the microwave expansion process. A semi-analytical solution was first obtained based on the case of a single bubble expansion in an infinite matrix. The dimensionless bubble radius and pressure are defined and found to be as exponential functions of dimensionless expansion time. The semi-analytical solution can qualitatively predict the radial expansion of EPS microsphere observed in a real-time experiment. To have an accurate prediction, a numerical solution was obtained to the model that couples the nucleation and expansion of multiple bubbles in a finite matrix. The results show that the numerical solution can quantitatively predict the radial expansion of EPS. A parameter sensitivity study was performed to examine the effect of each parameter over the expansion process.

Dissolved and Colloidal substances (DisCo) and metals are released from wood during thermomechanical pulp (TMP) production. The mechanical treatment causes that these components have a tendency to accumulate in process waters, as the water circulation systems in integrated paper mills are being closed. Disturbances such as pitch depositions on the paper machine (pitch problems), specks in the paper, decreased wet and dry strength, interference with cationic process chemicals, and impaired sheet brightness and friction properties appear in the presence of DisCo substances. The presence of transition metal ions such as manganese results in higher consumption of bleaching chemicals (hydrogen peroxide) and lowers the optical quality of the final product, and addition of complexing agents, such as EDTA or DTPA, to prevent this is needed. The never ending trends to decrease water consumption and increase process efficiency in pulp and paper production stress that it is very important both to know the effects of wood substances on pulping and papermaking and to be able to remove them in an efficient way. Carried out investigations presented in this thesis show that the lipophilic extractives can be removed from TMP press water to high extent. A 90% decrease in turbidity and a 91% removal of lipophilic extractives from TMP press water can be obtained by addition of a cationic surfactant as foaming agent during flotation. Additionally, fibres located in TMP press water are not removed with the foam fraction but purified. A retained concentration of hydrophilic extractives in the process water indicates that the flotation is selective. Moreover, by introduction of a new recoverable surface active complexing agent, a chelating surfactant, manganese ions in the form of chelates can be successfully removed from the pulp fibres and separated from the process water in the same flotation process. iii The findings presented above indicate new possibilities for internal water cleaning and decreased emissions to water if flotation technology is applied in an integrated mechanical pulp mill. / ReGain/FORE

Dissolved oxygen has previously been shown to affect the colour and sensory properties of red and white wine during storage. A number of different wines and wine based sparkling ciders are made at Kiviks Musteri AB. The aim of this work is to study the effects of dissolved oxygen and different enological treatments on sensory quality and colour of red wine and sparkling apple cider during storage at different temperatures. The effects of fermentation and fining on foaming ability of pear wine are also studied.   Samples of red wine were taken after different processing steps such as pumping, sulphuration, pasteurization and filling. To evaluate the effects of the processes on the wine, dissolved oxygen, colour and free SO2 were measured in each. Measurements were also made on samples of red wine stored at either 38°C or room temperature for different amounts of time. Sensory evaluations were also made of the wine samples. Colour was measured by measuring absorbance at 420, 520 and 620 nm. Dissolved oxygen was also measured after different processing steps during production of apple cider. To study the effects of dissolved oxygen on cider, three different batches of apple cider were produced, with different concentrations of dissolved oxygen. The samples were stored at either 38°C or room temperature for one week. Measurements of absorbance at 420 nm and free SO2, along with sensory evaluation were made on the cider samples before and after storage. Fermentation and fining of pear wine were made in small scale and the foaming ability was compared to that of large scale factory produced wine.   Pumping and filling had negative impact on the flavour of red wine. Colour intensity increased while free SO2 decreased during storage of red wine. The sensory quality decreased during storage and a higher storage temperature had a distinctive impact on this decrease. Dissolved oxygen had no noticeable effect on changes in sensory properties of neither red wine nor cider during storage. A higher concentration of dissolved oxygen was correlated to a higher increase in colour intensity of red wine though. A higher decrease was also seen in free SO2 in red wine samples with higher dissolved oxygen content when stored at 38°C. Fermentation had a large impact on foaming properties of pear wine. Small scale wine fermentation resulted in much lower foaming ability than large scale fermentation. / Syrehalten i viner har i tidigare studier visat sig kunna påverka både färg- och smakförändringar i vinerna under längre tids lagring. På Kiviks Musteri AB i Skåne produceras en mängd olika sorters vin och vinbaserade cidrar. Målet med den här studien är att studera vilken effekt syrehalten har på smak och färg i viner och cidrar från Kiviks Musteri som får lagras i olika temperaturer. Effekten av olika processteg under produktionen studeras också. Slutligen studeras även hur skumbildningen i päronvin påverkas av jäsning och klarning av vinet.   Prover av rödvin togs efter de olika processtegen vinet genomgår på Kiviks Musteri. Proverna lagrades olika länge i antingen 38°C eller rumstemperatur. Färgstyrka och smak analyserades på proverna före och efter lagringen. Syrehalten analyserades också i proverna direkt efter att de tagits och svavelhalten i proverna analyserades före och efter lagringen för att mäta hur mycket proverna oxiderades under lagringen. Mätningar av syrehalt gjordes även efter olika processteg under produktionen av äppelcider på Kiviks Musteri. Vilken effekt syrehalten har på äppelcider studerades genom att tre olika satser äppelcider med olika syrehalt tillverkades. Prover från dessa lagrades en vecka i antingen 38°C eller rumstemperatur. Därefter analyserades färgstyrka, svavelhalt och smak på proverna. Hur skumbildning i päronvin påverkas av jäsning och klarning studerades genom att päronvin fick jäsa och klarnas antingen i stor skala i musteriets tankar eller i liten skala på ett laboratorium. Skumbildningen mättes genom ett test där vinprover blandades med kolsyrat vatten.   De processer som inverkade starkast på smaken på rödvin var pumpning och tappning, vilka gav tydliga smakförsämringar. När rödvin lagrades så minskade svavelhalten medan färgstyrkan ökade. En försämring av smaken skedde också under lagringen, särskilt när vinet lagrades i 38°C. Syrehalten hade ingen tydlig påverkan på smaken av vare sig rödvin eller äppelcider. Syrehalten i rödvin hade däremot ett svagt samband med ökningen i förgstyrka i rödvin. Syrehalten hade även ett samband med minskningen av svavelhalten i de prover av rödvin som lagrades i 38°C. Skumbildningen i päronvin påverkades väldigt starkt av jäsningen, medan klarningen hade begränsad effekt. Skumbildningen var vesäntligt mycket lägre i päronvin som jäst i liten skala på laboratoriet än i det vin som jäst i musteriets tankar.

Injection molding technology is utilized for a wide range of applications from mobile phone covers to bumper fascia of automotive vehicles. Foam injection molding (FIM) is a branched manufacturing process of conventional injection molding, but it was designed to take advantage of existing foaming technology, including material cost saving and weight reduction, and to provide additional benefits such as improvement in dimensional stability, faster cycle time, and so on. Gas-assisted injection molding (GAIM) is another supplemental technology of injection molding and offers several advantages as well. This thesis study takes the next step and develops innovative gas-assisted foam injection molding (GAFIM) technology, which is the result of a synergistic combination of two existing manufacturing technologies, FIM and GAIM, in order to produce a unique thermoplastic foam structure with proficient acoustic properties. The foam structure manufactured by GAFIM consists of a solid skin layer, a foam layer, and a hollow core; and its 6.4-mm thick sample outperformed the conventional 22-mm thick polyurethane foam in terms of the acoustic absorption coefficient. With respect to foaming technology, GAFIM was able to achieve a highly uniform foam morphology by completely decoupling the filling and foaming phases. Moreover, the additional shear and extensional energies from GAFIM promoted a more cell nucleation-dominant foaming behavior, which resulted in higher cell density and smaller cell sizes with both CO2 and N2 as physical blowing agents. Lastly, it provided more direct control of the degree of foaming because the pressure drop and pressure drop rate was controlled by a single parameter, that being the gas injection pressure. In summary, innovative, gas-assisted foam injection molding technology offers not only a new strategy to produce acoustically functioning thermoplastic foam products, but also technological advantages over the conventional foam injection molding process. Gas-assisted foam injection molding can become the bedrock for more innovative future applications.

Injection molding technology is utilized for a wide range of applications from mobile phone covers to bumper fascia of automotive vehicles. Foam injection molding (FIM) is a branched manufacturing process of conventional injection molding, but it was designed to take advantage of existing foaming technology, including material cost saving and weight reduction, and to provide additional benefits such as improvement in dimensional stability, faster cycle time, and so on. Gas-assisted injection molding (GAIM) is another supplemental technology of injection molding and offers several advantages as well. This thesis study takes the next step and develops innovative gas-assisted foam injection molding (GAFIM) technology, which is the result of a synergistic combination of two existing manufacturing technologies, FIM and GAIM, in order to produce a unique thermoplastic foam structure with proficient acoustic properties. The foam structure manufactured by GAFIM consists of a solid skin layer, a foam layer, and a hollow core; and its 6.4-mm thick sample outperformed the conventional 22-mm thick polyurethane foam in terms of the acoustic absorption coefficient. With respect to foaming technology, GAFIM was able to achieve a highly uniform foam morphology by completely decoupling the filling and foaming phases. Moreover, the additional shear and extensional energies from GAFIM promoted a more cell nucleation-dominant foaming behavior, which resulted in higher cell density and smaller cell sizes with both CO2 and N2 as physical blowing agents. Lastly, it provided more direct control of the degree of foaming because the pressure drop and pressure drop rate was controlled by a single parameter, that being the gas injection pressure. In summary, innovative, gas-assisted foam injection molding technology offers not only a new strategy to produce acoustically functioning thermoplastic foam products, but also technological advantages over the conventional foam injection molding process. Gas-assisted foam injection molding can become the bedrock for more innovative future applications.

abstract: A recent joint study by Arizona State University and the Arizona Department of Transportation (ADOT) was conducted to evaluate certain Warm Mix Asphalt (WMA) properties in the laboratory. WMA material was taken from an actual ADOT project that involved two WMA sections. The first section used a foamed-based WMA admixture, and the second section used a chemical-based WMA admixture. The rest of the project included control hot mix asphalt (HMA) mixture. The evaluation included testing of field-core specimens and laboratory compacted specimens. The laboratory specimens were compacted at two different temperatures; 270 °F (132 °C) and 310 °F (154 °C). The experimental plan included four laboratory tests: the dynamic modulus (E*), indirect tensile strength (IDT), moisture damage evaluation using AASHTO T-283 test, and the Hamburg Wheel-track Test. The dynamic modulus E* results of the field cores at 70 °F showed similar E* values for control HMA and foaming-based WMA mixtures; the E* values of the chemical-based WMA mixture were relatively higher. IDT test results of the field cores had comparable finding as the E* results. For the laboratory compacted specimens, both E* and IDT results indicated that decreasing the compaction temperatures from 310 °F to 270 °F did not have any negative effect on the material strength for both WMA mixtures; while the control HMA strength was affected to some extent. It was noticed that E* and IDT results of the chemical-based WMA field cores were high; however, the laboratory compacted specimens results didn't show the same tendency. The moisture sensitivity findings from TSR test disagreed with those of Hamburg test; while TSR results indicated relatively low values of about 60% for all three mixtures, Hamburg test results were quite excellent. In general, the results of this study indicated that both WMA mixes can be best evaluated through field compacted mixes/cores; the results of the laboratory compacted specimens were helpful to a certain extent. The dynamic moduli for the field-core specimens were higher than for those compacted in the laboratory. The moisture damage findings indicated that more investigations are needed to evaluate moisture damage susceptibility in field. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2011

O estado do Rio Grande do Sul é o terceiro maior produtor de pedras preciosas do Brasil, atrás apenas de Minas Gerais e da Bahia, destacando-se a produção de ágatas na região de Salto do Jacuí. Na lavra e beneficiamento são produzidos grandes quantidades de resíduos que estão a espera de destino e utilização ambientalmente correta. De modo específico, este trabalho avaliou a possibilidade de utilização do resíduo de ágata rolada na fabricação de blocos de concreto celular espumígeno (BCCE), utilizados como blocos de vedação na construção civil. Adicionalmente, desenvolveu-se uma mistura de dois agentes espumígenos provenientes de ácidos graxos de coco, como agente incorporador de ar, pela adição de espuma pré-formada. A metodologia de produção foi baseada no modelo de produção dos blocos de uma pequena indústria na Região de Passo Fundo/RS, que produz e comercializa BCCE. Em um estudo prévio de bancada, foram estudadas a composição da espuma, a granulometria do resíduo, o teor de água e o tempo de mistura. Os materiais componentes do BCCE são resíduo de sílica de pedras roladas de ágatas (SiO2 - 92,5%), espuma preparada com ácidos graxos de coco, água de qualidade potável e cimento como agente aglomerante. Nos testes de bancada, foram confeccionados 36 corpos de prova, em forma cilíndrica, de tamanho 50 mm de diâmetro por 100 mm de altura, com diferentes volumes de ar incorporado, divididos em três grupos. As amostras foram deixadas durante 28 dias à temperatura ambiente, em processo de cura, e após foram analisados quanto à resistência à compressão, densidade e distribuição das bolhas de ar. Os resultados foram avaliados pela Análise de Variância e demonstraram que o Grupo II apresentou densidade de 430 Kg/m3, e resistência de 0,92 MPa. Este resultado está próximo do atendimento aos requisitos da norma para classe de resistência de < 400 Kg/cm3 (NBR 13438, 2013). / The state of Rio Grande do Sul is the third largest producer of gemstones in Brazil, only losing to the states of Minas Gerais and Bahia, and agate production stands out in the region of Salto do Jacuí. Great amounts of waste, which are waiting for environmentally correct destination and use, are produced in mining and processing. Particularly, this study assessed the potential use of rolling waste of agates in civil construction, and the manufacturing of foam concrete blocks as a full substitute for sand. Additionally, a mixture was made of two foaming agents derived from coconut fatty acids as air-developer agent, and as hydraulic binder the Portland CP V ARI-RS cement. The production methodology was based on the production model of the blocks in a small industry, which produces and sells foam concrete blocks in the region of Passo Fundo, RS, Brazil. In a previous bench study the parameters foam composition, residue granulometry, water content, and mix time were adequate and later replicated industrially. The materials composing foam concrete blocks are rolled agate stones silica (SiO2 – 92.5%), foam from coconut fatty acids, fresh water, and cement as binder. In bench tests, 36 cylindrical specimens were produced, with 50 mm of diameter and 100 mm of height, with different volumes of incorporated air, divided into three groups. The samples were kept at room temperature for 28 days with healing process, and after that, the resistance to compression, density, and air bubbles distribution were analyzed. Results were assessed by Analysis of Variance, and showed that Group II presented density of 430 Kg/m3 and resistance of 0.92 MPa. This result is close to meeting the requirements of the norm for resistance class of < 400 Kg/cm3 (NBR 13438, 2013).

O estado do Rio Grande do Sul é o terceiro maior produtor de pedras preciosas do Brasil, atrás apenas de Minas Gerais e da Bahia, destacando-se a produção de ágatas na região de Salto do Jacuí. Na lavra e beneficiamento são produzidos grandes quantidades de resíduos que estão a espera de destino e utilização ambientalmente correta. De modo específico, este trabalho avaliou a possibilidade de utilização do resíduo de ágata rolada na fabricação de blocos de concreto celular espumígeno (BCCE), utilizados como blocos de vedação na construção civil. Adicionalmente, desenvolveu-se uma mistura de dois agentes espumígenos provenientes de ácidos graxos de coco, como agente incorporador de ar, pela adição de espuma pré-formada. A metodologia de produção foi baseada no modelo de produção dos blocos de uma pequena indústria na Região de Passo Fundo/RS, que produz e comercializa BCCE. Em um estudo prévio de bancada, foram estudadas a composição da espuma, a granulometria do resíduo, o teor de água e o tempo de mistura. Os materiais componentes do BCCE são resíduo de sílica de pedras roladas de ágatas (SiO2 - 92,5%), espuma preparada com ácidos graxos de coco, água de qualidade potável e cimento como agente aglomerante. Nos testes de bancada, foram confeccionados 36 corpos de prova, em forma cilíndrica, de tamanho 50 mm de diâmetro por 100 mm de altura, com diferentes volumes de ar incorporado, divididos em três grupos. As amostras foram deixadas durante 28 dias à temperatura ambiente, em processo de cura, e após foram analisados quanto à resistência à compressão, densidade e distribuição das bolhas de ar. Os resultados foram avaliados pela Análise de Variância e demonstraram que o Grupo II apresentou densidade de 430 Kg/m3, e resistência de 0,92 MPa. Este resultado está próximo do atendimento aos requisitos da norma para classe de resistência de < 400 Kg/cm3 (NBR 13438, 2013). / The state of Rio Grande do Sul is the third largest producer of gemstones in Brazil, only losing to the states of Minas Gerais and Bahia, and agate production stands out in the region of Salto do Jacuí. Great amounts of waste, which are waiting for environmentally correct destination and use, are produced in mining and processing. Particularly, this study assessed the potential use of rolling waste of agates in civil construction, and the manufacturing of foam concrete blocks as a full substitute for sand. Additionally, a mixture was made of two foaming agents derived from coconut fatty acids as air-developer agent, and as hydraulic binder the Portland CP V ARI-RS cement. The production methodology was based on the production model of the blocks in a small industry, which produces and sells foam concrete blocks in the region of Passo Fundo, RS, Brazil. In a previous bench study the parameters foam composition, residue granulometry, water content, and mix time were adequate and later replicated industrially. The materials composing foam concrete blocks are rolled agate stones silica (SiO2 – 92.5%), foam from coconut fatty acids, fresh water, and cement as binder. In bench tests, 36 cylindrical specimens were produced, with 50 mm of diameter and 100 mm of height, with different volumes of incorporated air, divided into three groups. The samples were kept at room temperature for 28 days with healing process, and after that, the resistance to compression, density, and air bubbles distribution were analyzed. Results were assessed by Analysis of Variance, and showed that Group II presented density of 430 Kg/m3 and resistance of 0.92 MPa. This result is close to meeting the requirements of the norm for resistance class of < 400 Kg/cm3 (NBR 13438, 2013).