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Quarry fines are by-products of the aggregate extraction and productionprocesses. Because such fine material cannot be marketed, it becomes aburden for the aggregate industry, resulting in stockpiles of financiallyunexploited material. Even though previous research has been focused onminimizing the generation of quarry fines, far too little attention has beenpaid to maximizing their utilization instead. The aim of this thesis is toinvestigate whether 0/2 mm and 0/4 mm quarry fines can be utilized asalternative materials in the construction industry, specifically in theunbound layer of a road or as filling against a bridge. The methodologyconsisted of four laboratory tests that investigated the water content,particle size distribution and percentage of filler content, optimummoisture content (OMC) and maximum dry density (MDD) relationshipas well as bearing capacity of the materials. The results show that theamount of filler content (<0.063 mm) can significantly impact thematerial’s water-holding capacity as well as its compaction capabilities.After comparing the bearing capacity measurements to the technicalrequirements of the Swedish Transport Administration, it was found thatthe 0/2 mm fits the necessary requirements for use in the unbound layerof either a flexible or rigid pavement but not as filling against a bridge.Further research is needed to determine the material’s relationship towater absorption and resistance to freezing and thawing cycles, as it isdifficult to assess its suitability for road construction solely on theseresults; however, despite its limitations, the study provides some valuableinsights into the potential applications of quarry fines.

En av de saker som avgör hyggesresters värde som bränsle är dess fukthalt. Det vore bra om det gick att uppskatta fukthalten hos hyggesrester som lagras utomhus i högar, utan att någon undersökning av materialet behöver göras. Syftet med detta examensarbete var att finna ett sätt att uppskatta fukthalten med hjälp av information om vädret, exempelvis nederbördsmängd, temperatur och molnighet, på den plats på vilken hyggesresterna lagras. Examensarbetet har inte lett fram till någon metod som på ett tillförlitligt sätt kan uppskatta fukthalten med kännedom endast om var (och därmed kännedom om ungefärlig väderlek) som hyggesresterna lagras. Fukthalten tycks i hög grad styras av andra faktorer än de som är kända i denna studie. De okända faktorerna är exempelvis trädslag, kvistarnas tjocklek, markbeskaffenhet och placering i förhållande till omgivande terräng.

The main objectives of this study were to develop an effective process to produce modified pea starch with enhanced enzyme resistance property (RS) for food applications. The work compares a non-chemical method (heat moisture treatment) versus a chemical method (crosslinking). One type of commercial pea starch (Nutri-Pea) was used exclusively as the raw material in this study. A number of methods were used to characterize the properties of the modified pea starches: water solubility index (WSI), titration (conversion, iodine value), intrinsic viscosity, infrared spectroscopy (FT-IR), Englyst digestion method, total starch content, and rapid visco analysis (RVA). The effects of heat-moisture treatment on native pea starch and enzyme treated pea starch were examined. The results showed that the produced samples with both native starch and enzyme treated starch exhibited a sharp increase in intrinsic viscosity. Overall, this method was deemed undesirable and not extensively examined past preliminary evaluations. The main focus of the study was on a citric acid crosslinking reaction, chosen for its food compliancy. A temperature of 120 oC was considered ideal for the reaction. FT-IR confirmed the presence of the citric acid incorporation in the starch samples. To improve the extent of reaction, Butanetetracarboxylic acid (BTCA) was considered as a replacement for citric acid and its treated samples showed higher conversion and lower water solubility index than that of the citric acid treated samples. Sodium propionate (NaP) was also considered in the reaction, this time as a food-grade catalyst and found to have minor benefit in cross-linking. BTCA/NaP treated sample reached the highest conversion of the study (96.8±2.3 %) and the lowest WSI (13.1±2.0 %), which increased the RS fraction of the starch from 18% to 32%. The RVA pasting profiles examined were too low to compare due to the high degree of cross-linking. Further improvements to RS were sought by debranching the starch before acid crosslinking. A BTCA/NaP treated sample with enzyme treatment showed a low WSI (31.7±2.3 %) yet substantially higher RS fraction (80.81±0.18 %). Similar to the non-debranched acid modified samples, there were no significant RVA pasting results because of the high cross-linking. Finally, crosslinking with an epoxidized oil was tested to continue looking at food-grade solution yet possible increase the rate of the crosslinking reaction. The results of WSI indicated that this method had little influence on cross-linking, possibly due to the low epoxidation efficiency of vegetable oils, as determined by iodine value. / Thesis / Master of Applied Science (MASc)

京都大学 / 新制・課程博士 / 博士(農学) / 甲第24655号 / 農博第2538号 / 新制||農||1097(附属図書館) / 学位論文||R5||N5436(農学部図書室) / 京都大学大学院農学研究科農学専攻 / (主査)教授 白岩 立彦, 教授 中﨑 鉄也, 教授 丸山 伸之 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Yes / Silica is one of the most efficient gas barrier materials, and hence is widely used as anencapsulating material for electronic devices. In general, the processing of silica is carried out at hightemperatures, i.e., around 1000◦C. Recently, processing of silica has been carried out from a polymercalled Perhydropolysilazane (PHPS). The PHPS reacts with environmental moisture or oxygen andyields pure silica. This material has attracted many researchers and has been widely used in manyapplications such as encapsulation of organic light-emitting diodes (OLED) displays, semiconductorindustries, and organic solar cells. In this paper, we have demonstrated the process optimization ofthe conversion of the PHPS into silica in terms of curing methods as well as curing the environment.Various curing methods including exposure to dry heat, damp heat, deep UV, and their combinationunder different environments were used to cure PHPS. FTIR analysis suggested that the quickestconversion method is the irradiation of PHPS with deep UV and simultaneous heating at 100◦C.Curing with this method yields a water permeation rate of 10−3g/(m2·day) and oxygen permeationrate of less than 10−1cm3/(m2·day·bar). Rapid curing at low-temperature processing along withbarrier properties makes PHPS an ideal encapsulating material for organic solar cell devices and avariety of similar applications. / King Saud University

Cross-laminated timber (CLT) is an emerging sustainable engineered material with unique properties that in many ways make it superior to conventional construction material. CLT was invented in the 1990s and the volume produced have increased worldwide since then. It can be used in the load bearing structure for walls and floor slabs in the different typologies, e.g. residential and office buildings.The hygroscopic nature of wood allows it to exchange moisture with the surrounding environment. This may lead to an alteration of properties of wood-based materials such as CLT and can be accompanied by deformations and stresses. These effects influence the CLT’s structural stability, durability and safety.This study focuses on the consequences of moisture content variations in CLT structures, including mechanical properties like modulus of elasticity and bending stiffness (EI). Temperature and relative humidity were measured over three years in three positions along the thickness direction of a slab element on the first floor of House Charlie, a four-storey timber office building located in Växjö, Sweden.The investigation was carried out by mathematical modelling applying MATLAB® software aiming to find the moisture content as a function of time and thickness from the real-world data of House Charlie. The focus was on determining changes in modulus of elasticity and bending stiffness in response to moisture variation. The results showed that the moisture content within a slab of the building varied periodically following the seasonal variation throughout the years. The moisture content at the bottom of the slab was significantly lower compared to two other positions. According to the linear regression analysis, a linear relationship between the moisture content (MC) and positions across the CLT slab at each time step was defined. High R2 values, above 0.9, show the goodness of the fitted model. Applying the MC as a function of time and thickness into an available relationship of modulus of elasticity (E) could predict stiffness versus varied MC in the next step. The modulus of elasticity decreased with an increase in the moisture content over the studied period with a higher variation range at the bottom of the slab. In the final step, bending stiffness was assessed as a function of the changed moisture content. Bending stiffness increased periodically over time, attributed to overall more dry-out of the slab with time.The reported results of the present study give new insight into the behaviour of CLT structure over longer time periods. The recurring pattern in alterations stems from the reliance of bending stiffness on the modulus of elasticity function, which is in turn influenced by the linear relationship with moisture content exhibiting cyclic characteristics. The minimum and maximum values for EI were 3.5×1012 Nmm2 and 3.71×1012 Nmm2, respectively, a variation of approximately ±2.5% around the average. As the time steps increased, the bending stiffness also increased, given the progressive growth of the modulus of elasticity over time.

The influence of silane treated amorphous fumed silica fillers on properties of the cured epoxy was examined in the first part of the study. Silica particles were treated with 3- aminopropyldiethoxymethylsilane (APDS) and 3-aminopropyltriethoxysilane (APTS) coupling agents. The filler and coupling agents decreased the mobility of the polymer chains in the vicinity of the filler leading to an increase in the activation energy for the glass transition and an increase in cooperativity. Fumed silica did not significantly affect moisture diffusion properties. Next, a linear dilatometer was used to investigate the effects of cure conditions, mold types, and the presence of filler in the model epoxy. These studies revealed that there was substantial shrinkage in the cured epoxy on heating it through its glass transition region. The shrinkage was determined to be the result of stress in the epoxy generated during cure and could be minimized by curing at lower temperatures, followed by a postcuring heat treatment. Additional free volume in the sample increased the magnitude of the shrinkage by allowing increased stress release through increased network mobility. Decreasing the polymer mobility by adding fillers decreased the observed shrinkage. The influence of the model epoxy crosslink density was examined by varying the content of 1,4-butanediol in the model system. Addition of 1,4-butanediol led to a decrease in the modulus and glass transition temperature, which resulted in a reduction in residual stress and subsequent shrinkage. Moisture uptake increased with the addition of 1,4-butanediol due to an increase in the free volume of the epoxy. However, even with greater moisture uptake, the addition of 1,4-butanediol to the epoxy increased its adhesion to quartz by promoting lower residual stress and increased energy dissipation. These results indicate that bulk diffusion of water is not the controlling factor in adhesive degradation in this system. / Ph. D.

Coal preparation plants use large quantities of water for cleaning processes. Upon cleaning, the spent water must be removed such that the final product moisture level meets market constraints. However, removal of free water from the surface of fine particles is difficult and costly, and often the results are less than desirable. Fine particles inherently have very large surface areas, and hence retain large amounts of water. Increased amounts of fines also cause denser particle packing, which creates relatively small capillaries in filter cakes and, thus, cause slower dewatering kinetics. As a result, dewatering costs for fine particles are much higher than for dewatering coarse particles. Considering the technical and economic issues associated with dewatering coal and mineral fines, an extensive matrix of laboratory- and pilot-scale dewatering tests have been conducted to evaluate the use of novel dewatering aids. The reagents are designed to lower the surface tension of water, increase the hydrophobicity of the particles to be dewatered, and increase the capillary radius by hydrophobic coagulation. All of these are designed to lower the moisture of the filter cakes produced in mechanical dewatering processes. Laboratory-scale dewatering tests confirmed that using the novel dewatering aids can lower the final cake moisture of coal by 20-50%, while increasing the dewatering kinetics. Several on-site, pilot-scale tests were conducted to demonstrate that the process of using the novel dewatering aids can be scaled. Based on the laboratory- and pilot-scale tests conducted, a scale-up model for the process of using the novel dewatering aids has been developed. It can predict the final cake moistures as a function of vacuum pressure, filtration time and specific cake weight. The model can be useful for the scale-up of vacuum disc filters (VDF) and horizontal belt filters (HBF). Simulation results indicate that dewatering aids can be very effective, especially when used in conjunction with HBF due to its ability to control cake thickness and drying cycle time independently. In light of the promising laboratory- and pilot-scale test results, an industrial demonstration of the novel dewatering aids has been conducted at the Smith Branch impoundment site, which contains 2.9 million tons of recoverable coal. When the reagent was used for dewatering flotation products using a VDF, the moisture content was reduced from 26 to 20% at 0.5 lb/ton of reagent addition and to 17.5% at 1 lb/ton. The use of the dewatering aid also improved the kinetics of dewatering, increased the throughput, and reduced the power consumption of vacuum pumps by 30%. The novel dewatering aids were also tested successfully for dewatering of kaolin clays. In this case, the mineral was treated with a cationic surfactant before adding the dewatering aids. This two-step hydrophobization process was able to reduce the cake moisture and also increase the throughput. / Ph. D.