In this study, the effect of a passive trapped-vortex cell on lift to drag (L/D) ratio of an FFA-W3-301 airfoil is studied. The upper surface of the airfoil was modified to incorporate a cavity defined by seven parameters. The L/D ratio of the airfoil is modeled using a radial basis function metamodel. This model is used to find the optimal design parameter values that give the highest L/D. The numerical results indicate that the L/D ratio is most sensitive to the position on an airfoil’s upper surface at which the cavity starts, the position of the end point of the cavity, and the vertical distance of the cavity end point relative to the airfoil surface. The L/D ratio can be improved by locating the cavity start point at the point of separation for a particular angle of attack. The optimal cavity shape (o19_aXX) is also tested for a NACA0024 airfoil.

Furthering our understanding of the physics of flapping flight has the potential to benefit the field of micro air vehicles. Advancements in micro air vehicles can benefit applications such as surveillance, reconnaissance, and search and rescue. In this research, flapping kinematics of a ladybug was explored using a direct linear transformation. A flapping mechanism design is presented that was capable of executing ladybug or other species-specific kinematics. The mechanism was based on a differential gear design, had two wings, and could flap in harsh environments. This mechanism served as a test bed for force analysis and optimization studies. The first study was based on a Box-Behnken screening design to explore wing kinematic parameter design space and manually search in the direction of flapping kinematics that optimized the objective of maximum combined lift and thrust. The second study used a Box-Behnken screening design to build a response surface. Using gradient-based techniques, this surface was optimized for maximum combined lift and thrust. Box-Behnken design coupled with response surface methodology was an efficient method for exploring the mechanism force response. Both methods for optimization were capable of successfully improving lift and thrust force outputs. The incorporation of the results of these studies will aid in the design of more efficient micro air vehicles and with the ultimate goal of leading to a better understanding of flapping wing aerodynamics and the development of aerodynamic models.

Though still in relative infancy, the field of flapping flight has potential to have a far-reaching impact on human life. Nature presents a myriad of examples of successful uses of this locomotion. Human efforts in flapping flight have seen substantial improvement in recent times. Wing kinematics are a key aspect of this study. This study summarizes previous wing trajectory generators and presents a new trajectory generation method built upon previous methods. This includes a novel means of commanding unequal half-stroke durations subject to robotic trajectory continuity requirements. Additionally, previous optimization methods are improved upon. Experimental optimization is performed using the new trajectory generation method and a more traditional means. Methods for quantifying and compensating for sensor time-dependence are also discussed. Results show that the Polar Fourier Series trajectory generator advanced rapidly through the optimization process, especially during the initial phase of experimentation. The Modified Berman and Wang trajectory generator moved through the design space more slowly due to the increased number of kinematic parameters. When optimizing lift only, the trajectory generators produced similar results and kinematic forms. The findings suggest that the objective statement should be modified to reward efficiency while maintaining a certain amount of lift. It is expected that the difference between the capabilities of the two trajectory generators will become more apparent under such conditions.

Peanut skins are a low-value byproduct of peanut blanching operations. They have been shown to contain significant levels of phenolic compounds with demonstrated antioxidant properties. The effects of two types of extraction methods: solid-liquid extraction (SLE) and microwave-assisted extraction (MAE) on the recovery of phenolic compounds from peanut skins were investigated. Response surface methodology was used to optimize extraction conditions based on total phenolic content (TPC), ORAC (oxygen radical absorbance capacity) activity and <i>trans</i>-resveratrol content. The protective effect of peanut skin extracts (PSE) against hydrogen peroxide (H₂O₂)-induced oxidative stress in human brain microvascular endothelial cells (HBMEC) and the effect of PSE on lipid oxidation in commercial peanut butter were also evaluated. In the SLE method, EtOH was found to be the most efficient extraction solvent followed by MeOH, water and EA. Despite EtOH extracts having a higher TPC, samples extracted with MeOH demonstrated slightly higher ORAC activity. Resveratrol was identified in MeOH extracts but was not found in EtOH, water or EA extracts. In the MAE procedure, the maximum predicted TPC under the optimized conditions was 144 mg phenols/g skins compared to 118 mg/g with SLE. The maximum predicted ORAC activity was 2789 μmol TE/g as opposed to 2149 μmol TE/g with the SLE method. MAE was able to extract more phenolic compounds (with higher antioxidant activity) in a faster time than the SLE procedure. In addition, resveratrol was identified in PSE derived from MAE although at relatively low levels. PSE were found to have some protective effects against oxidative stress in HBMEC. Higher doses of PSE appeared to have a slightly cytotoxic effect. However, the data were highly variable which made it difficult to arrive at any definitive conclusions regarding the potential benefits of PSE in preventing oxidative damage to cells. In the PB experiment, hexanal levels over the storage period were not high enough for the samples to be considered oxidized. However, hexanal values of PB samples treated with PSE were lower than the control throughout storage, which suggests that PSE may provide some protection against oxidation of PB. / Ph. D.

Combining chemotherapeutics to treat malignant tumors has been shown to be effectivein preventing drug resistance, tumor recurrence, and reducing tumor size. We modeledcombination drug therapy in PC-3 human prostate cancer cells using mixture design responsesurface methodology (MDRSM), a statistical technique designed to optimize compositions thatwe applied in a novel manner to design combinations of chemotherapeutics. Conventionalchemotherapeutics (mitoxantrone, cabazitaxel, and docetaxel) and natural bioactive compounds(resveratrol, piperlongumine, and flavopiridol) were used in twelve different combinationscontaining three drugs at varying concentrations. Cell viability and cell cycle data werecollected and used to plot response surfaces in MDRSM that identified the most effectiveconcentrations of each drug in combination. MDRSM allows for extrapolation of data fromthree or more compounds in variable ratio combinations, unlike the Chou-Talalay method.MDRSM combinations were compared with combination index data from the Chou-Talalaymethod and were found to coincide. We propose MDRSM as an effective tool in devisingcombination treatments that can improve treatment effectiveness, and increase treatmentpersonalization because MDRSM measures effectiveness rather than synergism, potentiation orantagonism.

[pt] Metal Organic Frameworks(MOFs) são compostos de coordenação que possuem íons ou clusters metálicos ligados a espécies orgânicas, formando uma rede porosa, cristalina e de elevada área superficial. Essas características despertaram interesse no desenvolvimento de materiais oriundos de MOFs e, possivelmente, utilizá-los como catalisadores na produção de combustíveis líquidos. Nesta pesquisa, a síntese do Co-MOF-71 foi realizada pelo método solvotérmico, misturando ácido tereftálico, obtido a partir da despolimerização por hidrólise alcalina do polietileno tereftalato (PET) reciclável, e nitrato de cobalto hexahidratado, em solução de N,N-dimetilformamida, etanol e água. Após reação a temperatura de 110, 130 e 150 graus C, o material foi caracterizado quanto a sua resistência térmica, através da análise termogravimétrica, a cristalinidade, na análise de difração de raios X, e, de forma qualitativa, a composição elementar, avaliada na análise de microscopia eletrônica de varredura com energia dispersiva. O planejamento de experimentos de Box-Behnken foi elaborado, variando-se três fatores (temperatura, concentração de ácido tereftálico e quantidade de cobalto), totalizando quinze reações. A Co-MOF-71 foi calcinada em atmosfera inerte de N2 a 500 graus C para gerar uma matriz carbônica contendo cobalto, da qual a área superficial específica foi medida por adsorção-dessorção de N2, aplicando-se o método de Brunauer-Emmett-Teller. Um modelo polinomial de segunda ordem foi aplicado, com sua respectiva análise de variância (ANOVA) e os efeitos das variáveis de entrada foram classificados, constatando que a temperatura não exerceu influência significativa na faixa aplicada. Em seguida, o modelo foi atualizado, atingindo coeficiente de determinação (R2) de 87,39 por cento, revelando o teor de ácido tereftálico como o efeito mais expressivo. Além disso, a superfície de resposta confirmou que o cenário de maior área superficial é alcançado ao adicionar excesso de ligante orgânico no sistema, consistente com o melhor resultado experimental (82 m2.g-1). / [en] MOFs (Metal-organic frameworks) are special compounds that can be an interesting alternative for heterogeneous catalysis, due their singularities like a porous and crystalline structure with high specific area. This work proposes an environmentally favorable production route of Co-MOF-71 derived material, starting with the depolymerization of PET from plastic waste to obtain terephthalic acid, which is the source of ligand BDC (1,4-benzenodicarboxylate). The synthesis of Co-MOF-71 was performed by solvothermal method and, optimizing the research, Box-Behnken design were developed with three independent variables: amount of terephthalic acid, cobalt content, and temperature. The samples were characterized by XRD, TGA, and SEM analysis before and after calcination at 500 degrees C. Finally, the specific surface area was measured by N2 adsorption-desorption, and a second-order polynomial model was suggested, with its respective analysis of variance (ANOVA), indicating that temperature has no significant influence in the applied range. Then, the model was updated, reaching the coefficient of determination (R2 ) of 87.39 percent and presenting the terephthalic acid content as the most relevant effect. Additionally, the response surface confirmed the scenario of higher surface area with excess BDC in the system, consistent with the best experimental result (82 m2 / g).

Immobilization of proteins by covalent coupling to polymeric materials offers numerous excellent advantages for various applications, however, it is usually limited by coupling strategies, which are often too expensive or complex. In this study, an electron-beambased process for covalent coupling of the model protein bovine serum albumin (BSA) onto polyvinylidene fluoride (PVDF) flat sheet membranes was investigated. Immobilization can be performed in a clean, fast, and continuous mode of operation without any additional chemicals involved. Using the Design of Experiments (DoE) approach, nine process factors were investigated for their influence on graft yield and homogeneity. The parameters could be reduced to only four highly significant factors: BSA concentration, impregnation method, impregnation time, and electron beam irradiation dose. Subsequently, optimization of the process was performed using the Response Surface Methodology (RSM). A one-step method was developed, resulting in a high BSA grafting yield of 955 mgm−2 and a relative standard deviation of 3.6%. High efficiency was demonstrated by reusing the impregnation solution five times consecutively without reducing the final BSA grafting yield. Comprehensive characterization was conducted by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), and measurements of zeta potential, contact angle and surface free energy, as well as filtration performance. In addition, mechanical properties and morphology were examined using mercury porosimetry, tensile testing, and scanning electron microscopy (SEM).

This study presents mathematical surrogate models, derived from finite element kinematic response data, to predict car crash-induced occupant head and neck injury risk for a broad range of impact velocities (10 – 45 mph), impact locations, and angles of impact (-45° to 45°). The development of these models allowed for wide-scale injury prediction while significantly reducing the overall required number of impact test cases. From these, increases in both the impact velocity and the impact’s locational proximity to the occupant were determined to result in the greatest head and neck injury risks. Additionally, strong interactions between the impact orientation variables (location and angle) produced significant changes in the head injury risk, while the neck injury risk was relatively insensitive to these interactions; likely due to the uniaxiality of the current standard neck injury risk metrics. Overall, this methodology showed potential for future applications in wide-scale injury prediction or vehicular design optimization.

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