A de-oiling step using a centrifuge ensures oil content reduction and improves the quality of fried snacks. A commercial deep-fat fryer with the basket loaded with potatoes and a sample holder was used to fry potato slices, non-pretreated, blanched in hot water (85°C/3.5min) and rinsed in 3 percent NaCl solution (25°C/5min). A de-oiling step (350 1 rpm and 457 1 rpm) for 1 min was conducted after the frying (145°, 165° and 185°C or 165°C) and cooling (0, 15, 30, 45 and 60 s or 0.60 and 120 s) steps. Lower frying temperature, higher centrifuge speed, and shorter cooling time resulted in the lowest oil uptake in potato chips. Pre-treatments (blanching and soaking) decreased (5 percent and by at least 10 percent), respectively, compared to the untreated chips. De-oiling led to increased hardness of the chips fried at 145° and 165°C (0 s cooling time), and the hardness decreased as cooling time. Pre-treatments (blanching and soaking) increased hardness (by 46 percent and 38 percent) and decreased work (by 20 percent and 27 percent), respectively, so that, during rupture, the pre-treated chips resulted in more crunchiness and firmness than the untreated chips. Potato chips showed less lightness and redness when fried at 145°C, and more lightness and redness when fried at 185°C; yellowness increased b* values as temperature increased. As cooling time increased, the lightness of the chips decreased, and the redness and the yellowness of the chips increased. Pre-treated samples resulted in increasing in lightness (L*) and yellowness (b*), whereas the redness (a*) values of the final products fluctuated. Higher frying temperature, centrifuge speed, and higher cooling time usually resulted in increasing shrinkage in thickness of potato chips; the chips fried at 165°C resulted in increasing in thickness. All the fried and de-oiled products resulted in a decrease in thickness, diameter, and volume except for the thickness of the chip soaked in NaCl, compared to raw slices. A consumer test showed that, blanching and de-oiling without cooling enhanced texture and overall quality of the chip, soaking and de-oiling improved the color, flavor, and the overall quality, and the two pre-treatments did not significantly influence the odor of the chip.

Sea otters (Enhydra lutris) have the densest fur of any animal, and the hairs function to trap a layer of air that is used for insulation. When a sea otter is born, it has a natal pelage (baby fur), and sea otters eventually molt that fur and replace it with a pelt resembling the adult fur. Sea otter fur is composed of 3 types of hairs: underhairs, intermediate hairs, and guard hairs. Sea otters are more susceptible to the negative effects of oiling from oil spills compared to other marine mammal species because they solely rely on fur for insulation. Though numerous studies have investigated the functional morphology of adult sea otter fur and how it is affected by oil, not much is known about the characteristics and insulative abilities of sea otter natal fur. To better understand the structure and function of sea otter fur, I examined the hair morphology and related it to the thermal function and buoyancy of southern sea otter (Enhydra lutris nereis) pelts across different age classes. Guard hair length, hair circularity, guard hair and underhair cuticular scales, and hair density of sea otter pelts were measured across six age classes: neonate, small pup, large pup, juvenile, subadult, and adult. Thermal conductivity and thermal resistance of sea otter pelts were measured under three treatment conditions: in air, in water, and oiled. Pelt buoyant force in water was also measured under three treatment conditions: control (normal), oiled, and washed (with Dawn® dish soap). To scale up to the whole animal and examine differences related to body size, I used these measurements to estimate total heat loss, whole-animal buoyancy force, and mass-specific buoyant force. I confirmed the timing of the transition between the natal fur and adult fur, which occurs some time in between the small pup and large pup age classes. I observed a consistent pattern in the hair circularity and shape of guard hairs across all age classes. It is important for all sea otters to have the ellipsoid shape of the guard hair so that the hairs can lie flat against the air layer to protect it in water. Comparisons of hair density indicated that sea otters with natal fur (neonate, small pups, and some large pups) have approximately 25-53% lower hair density than older age classes with the adult-type pelage. This thinner hair density may explain why young sea otters are always on their mother’s belly to stay out of the cold water. When I examined the thermal function of the fur in air, I found that pups with natal fur have less efficient but equally effective thermal insulation. However, when I scaled up the thermal findings using body morphometrics and created a volume-based heat loss model, it was clear that younger sea otters have substantially more heat loss for their body size, compared to older age classes. Values for oiled heat loss demonstrated the vulnerability associated with sea otters relying on fur for insulation, and the large surface area to volume ratio associated with a small body size. It is already a high energy requirement for sea otters to maintain mammalian body temperate in cold water, and when the fur becomes oiled, the severe reduction of their insulation can cost them even more energy. Across age classes, there was no difference in the buoyant force of the fur when I focused on the pelt samples from the laboratory-based experiments. When I scaled up the pelt buoyant force values to the whole animal using body mass, total body length, and surface area, it became clear that buoyant force varied across sea otter age classes. The smaller body size present in younger sea otter age classes allows for a higher mass-specific fur buoyant force. The larger size and higher hair density in adult sea otters explains the higher whole-animal fur buoyant force, as more individual hairs allow for more air to be trapped within the fur. Oiling of the fur reduces the overall buoyancy, and washing the pelts with Dawn® did not consistently restore the air layer in the fur. In summary, the results of these studies indicate that the success of sea otters is due to the overall shape and structure of the individual hairs, along with the incredibly high hair density. The different hair types function together to trap the air layer in the fur to provide sufficient insulation. Ultimately, all ages of sea otters are vulnerable to the effects of oiling, with younger sea otters being the most susceptible.

The effects of polymer concentration and solvents on cocrystal morphology of low solubility drugs were investigated, both of which had an impact. The melting temperatures also decreased with increasing polymer concentration. Placing the binding agent, benzene, at different interfaces induced morphological changes, such as formation of porous cocrystals. Previously liquid-liquid phase separation (LLPS) has been reported as a hindrance in the crystallisation process impeding further development. A phase diagram was constructed, and different phases were categorised into 4 types. After separation of the highly concentrated amorphous Oil Phase II, it was prone to gradual crystallisation. Crystallisation took place over 30-60 minutes; this allowed the in-situ monitoring. A novel cocrystallisation technique was developed; from (LLPS). Cocrystals of indomethacin with saccharin and nicotinamide were obtained by mixing Oil Phase II with the coformers. In-situ monitoring by spectroscopic had gradual changes in spectra; characteristic peaks increased in height and area with the formation of crystals until the reaction was complete. With crystal formation, the XRD spectra gradually had a sharper baseline due to a decrease in the amorphous indomethacin. The photoluminescence (PL) spectra displayed several peaks coupling into one large hump together with increasing intensity as the sample crystallised. There was a shift in the peak absorbance of the pure drug crystals obtained from LLPS and the indomethacin:saccharin cocrystal obtained from LLPS. Amorphous stabilisation was achieved by mixing polymer (PVP) with Oil Phase II. There were no changes to the XRD diffractogram as the sample did not undergo crystallisation.

L’intérêt croissant de l’industrie pour les matériaux composites thermoplastiques est motivé par leurs propriétés de thermoformabilité, de recyclabilité ainsi que leurs capacités de cadences de production élevées. Le développement de matériaux pré-imprégnés thermoplastiques, apparus dès les années 1980, s’est imposé comme un moyen efficace de contourner les fortes viscosités des polymères utilisés en réduisant la distance d’écoulement des polymères à l’état « fondu ». Cette étude s’est plus particulièrement intéressée au développement de composites à base de tissus de verre et de carbone pré-imprégnés par un latex acrylique, le TPREG I. En outre, les propriétés mécaniques élevées des matrices acryliques, alliées à un coût relativement faible, en font un matériau intéressant, de nature à permettre un saut technologique dans la conception et la fabrication de composites structuraux à matrice organique. Notre étude s’est concentrée sur la mesure de l’adhésion à l’interface fibre/matrice acrylique car cette région est au cœur du transfert de charge de la matrice vers les fibres et conditionne donc les propriétés mécaniques du composite. Nous avons choisi d’évaluer l’adhésion interfaciale en combinant des analyses de mouilllage avec des tests mécaniques aux échelles microscopique et macroscopique. Le test micromécanique de la microgoutte permet de mettre en évidence le rôle central de l’ensimage des fibres sur la contrainte de cisaillement interfaciale. L’adhésion thermodynamique, déterminé par des mesures d’énergie de surface, est en accord avec la contrainte de cisaillement et souligne l’influence de la polarité de l’ensimage. A l’échelle macroscopique, les essais de traction hors-axe sur composites unidirectionnels permettant de solliciter l’interface en cisaillement quasi-plan ont mis en exergue une corrélation entre les échelles micro et macro. L’étude a également permis de dégager une forte augmentation de l’adhésion grâce à une modification de la matrice acrylique, ainsi qu’une dégradation des propriétés interfaciales à l’échelle micro par vieillissement hydrolytique. Cette étude constitue une première base de données concernant les propriétés interfaciales de composites thermoplastiques acryliques et démontre l’importance d’une étude multi-échelles dans la conception de nouveaux composites. / The present study was initiated by the development of a new processing route, i.e. latex-dip impregnation, for thermoplastic (TP) acrylic semi-finished materials. The composites resulting from thermocompression of TPREG I plies were studied by focusing of interfacial adhesion. Indeed the fiber/matrix interface governs the stress transfer from matrix to fibers. Thus, a multi-scale analysis of acrylic matrix/fiber interfaces was conducted by considering microcomposites, as models for fiber-based composites, and unidirectional (UD)macro-composites. The study displayed various types of sized glass and carbon fibers. On one hand, the correlation between thermodynamic adhesion and practical adhesion, resulting from micromechanical testing, is discussed by highlighting the role of the physico-chemistry of the created interphase. Wetting and thermodynamical adhesion are driven by the polarity of the film former of the sizing. On the other hand, in-plane shear modulus values from off-axis tensile test results on UD composites are consistent with the quantitative analyses of the interfacial shear strength obtained from microcomposites. More specifically, both tests have enabled a differentiation of interface properties based on the fiber sizing nature for glass and carbon fiber-reinforced (micro-)composites. The study of overall mechanical and interface properties of glass and carbon fiber/acrylic composites revealed the need for tailoring interfacial adhesion. Modifications of the matrix led to successful increases of interfacial adhesion in glass fiber/acrylic composites. An additional hygrothermal ageing study evidenced a significant loss of interfacial shear strength at micro-scale which was not observed for UD composites. The results of this study are a first step towards a database of relevant interface properties of structural TP composites. Finally, the analyses of interfaces/phases at different scales demonstrate the importance of a multi-scale approach to tailor the final properties of composite parts.