Content: In this study, equipped charcoal of Ficus carica without impregnation, impregnated with potassium hydroxide (KOH), zinc chloride (ZnCl2) and phosphoric acid (H3PO4) was used for sorption comparison of trivalent chromium from tannery wastewater. The equipped charcoal is characterized before and after used by Fourier transforms infrared spectroscopy (FT-IR). The quantitative elemental analysis is performed of the charcoal using PGT Energy dispersive X-ray spectrometry (EDX). The trivalent chromium sorption efficacy of charcoal was examined investigating charcoal dose, contact time, and relative pH parameters. Batch sorption test revealed that Ficus carica charcoal without impregnation had the maximum sorption capacity of trivalent chromium as depicted Fig. 1a. At the same conditions, trivalent chromium sorption on the Ficus carica charcoal without impregnation, impregnated with potassium hydroxide, zinc chloride and phosphoric acid was 98.9%, 98.8%, 8.9 and 2.5%, respectively. It is noticeable that without impregnation charcoal has a higher sorption capacity. Conversely, impregnation with chemical required cost involvement, time-consuming, long process time, and safe. Fig.1b depicts a shift in the peak intensity which indicated the change of frequency in the functional groups of the charcoal due to chromium adsorption. It indicates various responsible functional groups for the removal of trivalent chromium through Ficus carica charcoal. The trivalent chromium removal efficiency with the Ficus carica charcoal without impregnation was achieved 98.9%. The study could be helpful to design the sorption of trivalent chromium from the tannery wastewater in-house prior to discharge. Take-Away: 1. Without impregnation, Ficus carica charcoal has a better trivalent chromium sorption capacity 2. Trivalent chromium sorption capacity was 98.9%

The technique to produce pulp has improved and become more complex throughout the years. The purpose of pulping is to liberate the wood fibers and it can be done in two ways, either by chemically or mechanically separating the fibers. This thesis will focus on the commonly used kraft pulping process for eucalyptus and especially on the impregnation stage and how it affects kappa number and alkali consumption. This is done by studying the alkali charge, impregnation time and temperature for the impregnation stage while maintaining constant cooking parameters. This project has shown that the impregnation temperature affects the alkali consumption more than the impregnation time. A correlation between alkali consumption in the impregnation and the kraft cook was seen. When the consumption is high in the impregnation stage, a lower consumption was observed in the cooking stage. / Tekniken för framställningen av trämassa har utvecklats och blivit mer komplex genom åren. Massaframsställningens syfte är att separera träfibrerna ifrån varandra vilket kan utföras på två sätt, antingen på kemisk eller mekanisk väg. Denna studie kommer att fokusera på den beprövade sulfatkokningen och då i synnerhet hur impregneringssteget påverkar kappa numret och alkali konsumtion. För att uppnå detta studeras basningen för alkalin, impregneringstid och temperatur under impregneringen samtidigt som de övriga parametrarna hålls konstanta. Detta projekt har visat att impregneringstemperaturen påverkar alkali konsumtionen mer än tiden den impregneras. Andra studier som exempelvis Weiping Ban and Lucian A. Lucia 2003 och Joni Lehto & Raimo Alén 2013 har har också påvisat denna relation mellan alkali konsumtion och impregneringstemperaturen. Denna studie har även visat en alkali konsumtionstrend mellan impregneringen och sulfatkoket. När konsumtionen är hög under impregneringen så är den lägre i koket.

The kraft process is a complex system with many variables, and though the process is fairly well understood, there is still much we do not know.      This thesis examines some aspects of the kraft process that could prove to be of interest for the pulp and paper industry, specifically, the impact of wood chip impregnation and of the chemical structure of xylan on spruce kraft pulp. The intent is to suggest modifications to the kraft process as it is used today.      The effect of wood chip impregnation varies with the prevalent conditions, and increases the effect of the subsequent kraft cook. Longer impregnation at a lower temperature was found to increase screened pulp yield, reduce shives content, make it possible to reach a certain kappa number at a lower H-factor, and make it possible to reach a certain kappa number at a lower total alkali consumption.      Xylan has previously been found to have a strength-enhancing effect on pulp, and the chemical structure of the xylan in question was found to be the main strength-enhancing factor. For spruce xylan, the structure that provides the largest increase in strength is not the same as the structure that increases the yield the most. Removing xylan was determined to have a negative impact on pulp strength.      Xylan extracted from agro waste can be used as an additive to increase pulp strength. This could be viable, especially when combined with the production of green plastics from hemicelluloses extracted from the agro waste.      A suggested configuration of a future pulp mill is presented, incorporating the following modifications to the now standard kraft cooking system: impregnation at a lower temperature for a longer time; extracting xylan-enriched black liquor at an early stage of the impregnation or cook, and adding this liquor at a late stage of the cook; terminating the cook at a higher kappa number; increasing oxygen delignification to compensate for the increased kappa number at the end of the cook, keeping the kappa number constant going into the bleaching plant; and adding agro-waste xylan during oxygen delignification. / <p>QC 20150525</p>

Cellulosic fibers sized from the macro-scale to the nano-scale were prepared hierarchically from kenaf bast fibers using chemicals. The process began with a hermetical alkaline retting followed by a bleaching treatment. The bleached fibers were hydrolyzed using inorganic acid, from which microfibers and cellulose nanowhiskers (CNWs) were fabricated. Inorganic nanoparticle impregnation (INI) was used to treat the retted fibers for the improvement of the interfacial compatibility between the fiber and polypropylene (PP) matrix. The retted fibers and INI-treated fibers were used as reinforcement for the PP polymer composites. Film casting process was used to make CNW/PVA composites. The hermetical retting process used in this study produced fibers with high cellulose contents (81-92%) by removing the lignin and hemicelluloses. Higher retting temperature resulted in higher fiber surface hardness and elastic moduli. The tensile strengths and tensile moduli of the fibers decreased as the temperature increased. The SEM images showed the micropores in the cell wall structure for the fibers retted at over 130°C, providing the possibility to anchor nanoparticles into the cell wall. Surface morphology of the INI-treated fibers was examined with SEM, and showed that the CaCO3 nanoparticle crystals grew onto the fiber surface. Energy-dispersive X-ray spectroscopy (EDS) was used to verify the CaCO3 particle deposits on the fiber surface. As the size scale of the fibers decreased, the fiber crystallinity increased from 49.9% (retted fibers) to 83.9% (CNWs). About 23% á-cellulose in the raw kenaf bast fibers had been converted into CNWs. The retted fibers without INI treatment had poor compatibility with the polypropylene matrix. The INI treatment improved the compatibility between the fibers and the PP matrix, resulting in an improvement in kenaf fiber/PP composite tensile moduli and tensile strengths. The CNWs prepared from kenaf bast fiber gave excellent reinforcement for PVA composites. A nine percent increase of CNWs in the CNW/PVA composites yielded significant improvements in tensile strength and modulus of about 46% and 152%, respectively, compared with pure PVA.

Stable dinuclear complexes bis(heptane-2,4,6-trionato)dicopper(II) [Cu2(daa)2], bis(1,5-diphenyl-1,3,5-pentanetrionato)dicopper(II) [Cu2(dba)2], bis(1,5-diphenyl-1,3,5-pentanetrionato)dicobalt(II) [Co2(dba)2], and [6,11-dimethyl-7,10-diazahexadeca-5,11-diene-2,4,13,15-tetranato(4-)-N7N10O4O13;O2O4O13O15] copper(II)cobalt(II) [(CuCo(daaen)] were supported on Cab-O-Sil by the batch impregnation technique. The supported samples were characterized by UV-Vis, elemental analysis, X-ray powder diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and thermal gravimetric analysis (TGA). Elemental analysis and TGA data confirm that the Cu2(daa)2 complex loses one of its coordinated ligands upon adsorption onto silica in THF at greater than 4.43 wt% Cu loading. By contrast, at all Cu loadings the Cu2(dba)2 complex was adsorbed on the silica surface in CH2Cl2 without loss of ligand. XRD and DRIFTS results confirmed the formation of Cu2(dba)2 multilayer films on the Cab-O-Sil surface for samples containing greater than 2.64 wt% copper. The dinuclear cobalt complex and copper-cobalt complex also do not lose their coordination ligands upon adsorption on the surface. These two metal complexes are amorphous and did not produce XRD patterns. However, DRIFTS results confirm that the binuclear cobalt complex and the copper-cobalt complex begin forming multilayer films between 1.21and 2.53 wt% Cu. The Cu2(dba)2/silica precatalysts were subsequently converted to the catalysts by decomposing the organic ligands at 450 degrees Celsius followed by activation with 2% H2 at 250 degrees Celsius and were evaluated for methanol synthesis and methanol decomposition reactions. Kinetic studies demonstrated that the 3.70% Cu/silica[Cu2(dba)2] catalyst is more active for methanol decomposition than it is for methanol synthesis. The supported dinuclear cobalt and copper-cobalt precatalysts were converted to the catalyst by heating at 450 degrees Celsius followed by activation of the catalysts with 50% H2. Four different catalysts, 3.5% Co/silica[Co2(dba)2], 6.7% Co/silica[Co2(dba)2], 2.3% Co/silica[CuCo(daaen)], and 5.5% Co/silica[Co2(daa)2] were evaluated for the Fischer-Tropsch reaction at 350 degrees Celsius in a batch reactor. The supported binuclear cobalt catalyst produced C1-C7 alkanes and a significant amount of CO2. By contrast, the catalyst formed from heterobinuclear CuCo(daaen) showed the ability to convert syngas to aromatics with a narrow product distribution. In addition, the 6.7% Co/silica[Co2(dba)2] multilayer catalysts have above 98% conversion rates and 60% liquid hydrocarbon selectivity in a flow reactor.

The utilization of fiber-based packages has started to take more place at the packaging sector but is still restricted by a lack of transparency. Today this challenge is tried to be solved by paying more attention on the characteristics of nanofibers and their possibilities. The usage of nanofibers is, however, facing issues such as long dewatering times, demand to modify pulp fibers and changes in production line machines. Therefore, the purpose of this study is to bring up new insights how to enhance the translucence in fiber-based packaging materials by an impregnation treatment without fiber modification, long dewatering time or toxic impregnation compounds. Four compounds sucrose octaacetate (SOA), sucrose acetate isobutyrate (SAIB), α-D-glucose pentaacetate (GPA) and polyvinylalcohol (PVA) were impregnated into a yellowish uncalendared base paper without surface sizing. The hypothesis was that it is possible to achieve significantly higher translucence of a glassine paper (&gt;&gt;50 %) by impregnation of a compound with a similar refractive index to cellulose and calendering. This study confirmed the hypothesis when calendered 23 % blade coated SAIB samples resulted in translucence over 64 %. At the same time, it was noticed that increase in density did not explain the increased translucence, but more important requirements were the properties of the impregnated compound such as melting point at room temperature, viscosity, amorphous structure and additives of the paper. It was also found that SAIB did not cause negative impacts on tensile strength or contact angle measurements. The results of this study offered fundamental information for the possible future steps towards transparent paper without pulp fiber modifications. / Användningen av fiberbaserade förpackningar ökar inom förpackningssektorn men är fortfarande begränsad av bristen på materialgenomskinlighet. Idag försöker man lösa denna utmaning genom att ägna mer uppmärksamhet åt nanofibrernas egenskaper och deras möjligheter. Användningen av nanofibrer står dock inför problem som långa avvattningstider, behov av att modifiera massafibrerna och förändringar i fiberlinjens utrustning. Därför är syftet med denna studie att ta fram nya insikter om hur man kan förbättra genomskinligheten i fiberbaserade förpackningsmaterial genom en impregneringsbehandling utan fibermodifieringar, långa avvattningstider eller giftiga impregneringskemikalier. Fyra föreningar; sackarosoktaacetat (SOA), sackarosacetatisobutyrat (SAIB), -D-glukospentaacetat (GPA) och polyvinyl alkohol (PVA) impregnerades i ett okalandrerat baspapper utan ytlimning. Hypotesen var att det är möjligt att uppnå signifikant högre genomskinlighet av ett glassinpapper (&gt;&gt;50%) genom impregnering av en förening med liknande brytningsindex som cellulosa följt av kalandrering. Denna studie bekräftade denna hypotes när kalandrerade 23 % bladbelagda SAIB-prover resulterade i genomskinlighet över 64 %. Samtidigt noterades att ökningen i densitet inte förklarade den ökade genomskinligheten utan viktigare krav var egenskaperna hos den impregnerade föreningen såsom smältpunkt vid rumstemperatur, viskositet, amorf struktur och tillsatser av papperet. Det visades också att SAIB inte orsakade negativ påverkan på draghållfasthet eller kontaktvinkelmätningar. Resultaten av denna studie visade grundläggande information för möjliga framtida steg mot transparent papper utan massafibermodifieringar.

Yes / Aluminium alloys are widely used structural materials in automotive, aerospace, and transportation, among several other notable industries. However, aluminium alloys' low hardness and poor tribological performance prevent potential use in applications requiring high contact pressures and wear resistance. This paper presents a novel two-step technique for enhancing the mechanical properties of the aluminium alloy by impregnating the surface with Ni-coating containing hard TiO2 nanoparticles using a high-intensity electric arc generated during tungsten inert gas welding. The results show that the process significantly changes the Microstructure and mechanical properties. The surface hardness increased from 0.48 GPa to 0.65 GPa with a corresponding change of Young's modulus from 15 GPa to 24 GPa of the treated surface.

No description available.

<p> The exploration of cathode materials and fabrication methods plays an important role in the development of solid oxide fuel cell (SOFC) technology. The objective of this study is first to optimize the cathode microstructure by the impregnation method, and then investigate the potential application of copper manganese spinel as a new cathode material with optimized microstructure and explore the reaction mechanism of the cathodes.</p> <p> The impregnation method was employed to fabricate a composite cathode with electrocatalyst particles dispersed in a framework of electrolyte material. The impregnation method is relatively easy to apply and yield the optimized microstructure, allowing extended three phase boundary length and absence of secondary phase formation during fabrication.</p> <p> The polarization performance of copper manganese spinel (CMO) impregnated YSZ cathodes was examined by adjusting catalyst particle size, electrode thickness and catalyst content. A critical thickness of 16.9±2.0 μm for the CMO-YSZ composite cathode was calculated from Tanner's model. Decreased catalyst particle size and a thickness close to the critical value were found to eliminate polarization loss. The composite cathode with 50 wt% CMO impregnation showed a polarization resistance as low as 0.3 Ωcm^2 at 750°C. At 800°C, an SOFC with CMO-YSZ composite cathode had a power density of 172 mW/cm^2, which was 2.5 times higher than the cell with the traditional LSM-YSZ composite cathode under the same conditions.</p> <p> The cathode reaction mechanism of CMO-YSZ and strontium doped lanthanum ferrite (LSCF) impregnated Gd doped ceria ( CGO) composite cathodes was studied, using impedance spectroscopy, cyclic voltammetry and current interruption techniques. Surface diffusion and mass transfer were determined to be the rate controlling steps for CMO-YSZ composite cathode at low and high temperatures, respectively. A low frequency process at low temperatures and at least two processes at high temperatures were identified as rate determining steps of LSCF -CGO composite cathodes. A cathodic current activation effect was observed on CMO-YSZ cathode under current passage. The catalytic activity of CMO was enhanced by the cathodic current and the effect existed in both long-term and short-term experiments.</p> <p> The results of this study suggest that copper manganese spinel has attractive properties as a new catalyst material for the cathodic reaction with the composite structure obtained by the impregnation method.</p> / Thesis / Master of Applied Science (MASc)

With advantages of high cation exchange capacity, swelling-shrinking property and large specific surface area, monmtorillonite is chosen as a carrier and modified with Fe3+ saturation for estrogen decontamination. 17β-Estradiol (βE2) has highest estrogenic activity among estrogens and is selected as representative compound. Rapid βE2 transformation in the presence of Fe3+ - saturated montmorillonite in aqueous system was observed and βE2 oligomers were the major βE2 transformation products. About 98% of βE2 were transformed into oligomers which are >107 times less water-soluble than βE2 and therefore are much less bioavailable and mobile. Fe3+ -saturated montmorillonite catalysis achieved highest βE2 removal efficiency at neutral solution pH and higher temperature. Common cations did not have impact on the reaction efficiency. Dissolved organic matter slightly reduced βE2 removal efficiency. Regardless of wastewater source, ~40% βE2 removal efficiency was achieved for wastewater effluents when they were exposed to same dosage of Fe3+ -saturated montmorillonite as that for simple water systems which achieved ~83% removal efficiency. For real wastewater that contained higher organic matter, higher dosage of Fe3+ -saturated montmorillonite would be needed to create available reaction sites for βE2. This thesis also reports that Fe3+ -saturated montmorillonite effectively deactivate wastewater microorganisms. Microbial deactivation rate was 92±0.6% when secondary wastewater effluent was mixed with Fe3+ -saturated montmorillonite at 35 mg/mL for 30 min, and further increased to 97±0.6% after 4-h exposure. Freeze-drying Fe3+ -saturated montmorillonite iii after each usage resulted in 82±0.5% microbial deactivation efficiency even after fourth consecutive use. For convenient application, Fe3+ -saturated montmorillonite was further impregnated into filter paper through wet-end addition and formed uniformly impregnated paper. Scanning electron microscopy (SEM) imaging showed Fe3+ -saturated montmorillonite was evenly dispersed over cellulose fiber surface. When filtering 50 mL and 200 mL water spiked with live Escherichia coli (E. coli) cells at 3.67×108 CFU/mL, Fe3+ -saturated montmorillonite impregnated paper with 50% mineral weight loading deactivated E. coli with 99% and 77%, respectively. Dielectrophoresis and impedance analysis of filtrate confirmed that the deactivated E. coli passing through Fe3+ -saturated montmorillonite paper did not have trapping response due to higher membrane permeability and conductivity. The results demonstrate feasibility of using Fe3+ -saturated montmorillonite impregnated paper for convenient point-of-use drinking water disinfection. / Ph. D.