218 research outputs found
Annotated Bibliography on O.K. Bouwsma Collection
No full textDr. Ronald Hustwit is the author of O.K. Bouwsma: A Philosophers Journey, Something About O.K. Bouwsma, An Annotated Bibliography of Bouwsma’s works, and an Index of The Bouwsma Collection at The Humanities Research Center, The University of Texas. He has edited five works of O.K. Bouwsma’s papers: Toward a New Sensibility, Without Proof or Evidence, Wittgenstein Conversations, Bouwsma’s Notes on Wittgenstein’s Philosophy and Bouwsma’s Commonplace Book.https://openworks.wooster.edu/bouwsma/1000/thumbnail.jp
Text of speech by Missouri House Representative O.K. Armstrong opposing amendment barring Japanese American doctor from practicing medicine
No full textText of Missouri House Representative O.K. Armstrong's speech in front of House of Representatives to oppose an amendment banning Japanese American Doctor Fujikawa from practicing medicine in the State Tubercular Sanatorium. Armstrong states that Dr. Fujikawa chose to leave the relocation center because his services were needed in the State Sanatorium, that without his assistance, 150 tubercular patients would be sent home. Armstrong mentions bravery of Japanese American combat regiment fighting in Italy and condemns racism and discrimination of Japanese Americans, stating "Dr. Fujikawa is not responsible for our war with Japan. For that matter the people of the Japanese Empire had no voice in their destiny, no control over the mad warlords who launched the attack at Pearl Harbor." He strongly opposes amendment preventing Dr. Fujikawa from practicing medicine both as an outcry against discrimination, and in support of Dr. Fujikawa, whose services are needed in the state of Missouri.The War Relocation Authority (WRA), together with the Wartime Civil Control Administration (WCCA), the Civil Affairs Division (CAD) and the Office of the Commanding General (OFG) of the Western Defense Command (WDC) operated together to segregate and house some 110,000 men women and children from 1942 to 1945. The collection contains documents and photographs relating to the establishment and administrative workings of the (WDC), the (WRA) and the (WCCA) for the year 1942
Leadership perceptions of third grade students based on both gender of the leader and gender of the student
No full textPlan BThe purpose of this study was to determine the relationship between the gender of third grade students at Longfellow Elementary and their rating of perceived leadership effectiveness of both males and females as measured by the Kapanke-Sproul scale. The subjects for this study were all of the third grade students at Longfellow Elementary School. This study utilized four pictures with written narrative descriptions attached. The students were each given a packet of four pictures with written narrative descriptions. Each packet contained an effective male leader, an effective female leader, an ineffective male leader, and an ineffective female leader. Half of the students received a picture of a male described as an effective leader while the other half of the students received a picture of a female with the same written description. Next, half of the students received a picture of a female with the description of an effective leader, and the other half of the students received a picture of a male with the same written description. Thirdly, half of the class was given a picture and written description of an ineffective male leader, while the other half of the students were given a picture of a female with the same written description. Lastly, half of the class was given a picture of a female with the a written description of an ineffective leader, and the other half of the class was given a picture of a male with the same written description. At the bottom of each written narrative description there were two questions, and the students were asked to rate their perception of effective leadership ability for each individual on a "Likert Scale." The results were analyzed to determine if gender of the leaders affected how they were perceived by the students. The results were also analyzed to determine if gender of the student affected whether males or females were perceived to be more effective leaders To this researcher's surprise, none of the findings were statistically significant. When looking at the raw data, it appeared that male students perceived male leaders as more effective and female students perceived female leaders to be more effective, but when the data was analyzed this was not the case. The data analysis showed that generally, males and females are perceived as equally effective, regardless of the gender of the student or the leader. The collective findings of this study resulted in the conclusion to accept the Null Hypothesis that there is no statistically significant difference in perceived leadership effectiveness of adult males versus females based upon gender of the third grade students. It is important to study gender issues to help understand what still needs to change to help eliminate sex-role stereotypes in society, occupations, and leadership roles. This information was used to make suggestions for future guidance curriculum to ensure gender equality
Exploitation of homogeneous isotropic turbulence models for optimization of turbulence remote sensing
No full textHomogeneous isotropic turbulence (HIT) models are compared, with respect to optimization of turbulence remote sensing. HIT models have different applications such as load calculation for wind turbines (Mann, 1998) or droplet track modelling (Pinsky and Khain, 2006). Details of vortices seem of less relevance for modelling `realistic measurements', where the single purpose is to retrieve the eddy dissipation rate (EDR). Without the need for modelling the vortices, a faster and simpler approach might be favorable. The cascade turbulence model (CTM) is suggested. The CTM solution is scale invariant and a fast solution for one-dimensional HIT modelling. In this presentation modelled radar measruments for scanning mode (rotating antenna) are compared for different HIT models. The consequences for turbulence remote sensing optimization are discussed
Design of a composite guitar
No full textToday’s acoustic guitars are getting increasingly expensive due to the worsening availability of the highest quality woods. Composites show great promise in replacing wood in acoustic guitars as they are lightweight, are not as sensitive to environmental effects and are much stronger. Current composite guitars however do not sound as good as their wooden counterparts. Therefore this thesis research has been set-up to create a composite material that can match wood acoustically and therefore have all the benefits in terms of environmental sensitivity and strength while not compromising the sound quality of the instrument. A new composite is developed and extensively tested. This composite consists of a carbon fibre reinforced polyurethane foam and has a comparable acoustic response to high quality spruce used for guitar soundboards. With this new composite a complete composite guitar is designed, manufactured and tested. The psychoacoustic analysis performed showed that the new composite guitar is considerably more wood like in its sound compared to current carbon fibre acoustic guitars.Aerospace EngineeringAircraft Structures and Material
Bonding Thermoplastic Polymers on Preconsolidated Thermoplastic Laminates by Additive Manufacturing
No full textBy 2050 Airbus has the ambition to fly an aircraft made mainly from additive manufactured parts. In order to reach this goal by 2050 different parts are being designed for additive manufacturing production processes. For example fuel engine nozzles, door hinges and seat belts. Fokker Aero Structures, Materialise NV and the faculty of Aerospace Engineering want to take a next step by developing a 3D spoiler demonstrator representing a group of aircraft spoilers, ailerons and flaps. The 3D spoiler demonstrator consists of a pre-consolidated CF laminate skin with an additive manufactured rear structure fitting in the wing of the aircraft. The rear structure is additive manufactured using the fused deposition modelling, abbreviated as FDM, technology and bonds to the pre-consolidated CF laminate skin by the principle of autohesion during additive manufacturing of the rear structure. Autohesion between the two polymers is dominated by pressure, temperature and time. Obtaining good shear strength at the interface, between the pre-consolidated CF laminate skin and the additive manufactured rear structure, is the first step in the design of the 3D spoiler demonstrator. By using an experimental additive manufacturing set-up the influence of the joint surface temperature, influenced by FDM working parameters, on the shear strength is investigated.Aerospace EngineeringAerospace Structures & MaterialsStructural Integrity & Composite
Mechanics of fused filament fabricated thermoplastics: Modelling the mesostructure
No full textIn this thesis, the relation between the manufacturing parameters and the mechanical properties of Fused Filament Fabrication (FFF) materials is analyzed to gain a better understanding of interaction between these two. The existing literature was first analyzed to get an understanding for the process, resulting in a proposed mesostructural and mechanical model of FFF materials. The model was constructed such that only the print settings plus the part weight and dimensions after printing are necessary to calculate the mesostructural dimensions. A sensitivity analysis was performed in order to get a better understanding of the limitations of the model. Subsequently a FEM model was used to verify the above model. This sensitivity analysis was performed using a sweep of different mesostructural parameters was done in order to see the impact on the mechanical properties by means of FEM and analytical-numerical methods. The sweep parameters are the aspect ratio, the infill coefficient and the shrink coefficient. The analytical-numerical methods were added for validation and to get a mathematical feel for the mechanical phenomena. The effect of the shapes and sizes of the filaments were assessed with the three sweeps on the stiffness and stress concentrations. The models did show mostly expected trends, which not all have not been fully described in literature before. In order to verify the mesostructural model, a sintering simulation of the 2D filament crosssections was performed in Comsol. The void shape evolution performed as expected, however the long cusps are found to form upward due to the competition for inflowing of other cusps nearby. This counteracts hypothesis from literature. Additionally, the Comsol simulation did not respond well to the external shrinking variable. The cause behind this is suspected to be in the flow solver having problems in solving around sharp cusps in the fluid mesh.Aerospace EngineeringAerodynamics, Wind Energy, Flight Performance & Propulsion (AWEP)Flight Performance & Propulsio
Drawing behavior of UHMWPE films made from solution casting: Influence of solvent quality
No full textUltra-High Molecular Weight Polyethylene (UHMwPE) fibers are well known for their very high specific mechanical properties such as tensile strength and Young’s modulus. The solution spinning/solid state drawing process invented in the late 70s at DSM enables the production of these UHMwPE fibers with outstanding mechanical properties. The achievable maximum draw ratio of the UHMwPE fibers dictates their mechanical properties. One of the possible ways to improve this maximum draw ratio (λmax) is by decreasing the quality of the solvent used for its production. Modifying the solvent in the production of UHMwPE fibers might be a way to achieve higher properties. The focus of this project is mainly to study the influence of different solvents on the production of high strength UHMwPE films/fibers. Various ways were used to decrease the quality of the solvent to gel cast UHMwPE films and then the effect of this solvent quality on the drawing properties was determined. Subsequently, the molecular between the entanglements (Me) of polyethylene chains in different solvents was investigated using shear rheology. Morphological analysis (SEM, XRD) was performed to understand the topology, crystallinity, crystal thickness of the films made in different solvents. It was found that solvent quality has a significant effect on the maximum attainable draw ratio. SEM analysis was able to distinguish between drawable and undrawable UHMwPE films. However, from XRD analysis it was found that the crystal thickness is not the controlling factor for the improvement in drawability. The required difference Me of polyethylene chains in different solvents was found but it was within the experimental accuracy which made it difficult to conclude. Furthermore, preliminary study of some of the selected solvents on the production of UHMwPE fibers was performed. The drawing results proved that one to one translation from gel casting (films) to solution spinning (fibers) process is not straightforward. And also suggested that optimization of the drawing conditions of fibers can possibly lead to achieve expected maximum draw ratios.Aerospace EngineeringAerospace Structures and Material
Evaluation of a Lightweight Composite Bottom Plate for Air Cargo Containers
No full textAir cargo containers are used to load luggage, freight, and mail on aircraft. They allow a large quantity of cargo to be bundled into a single unit. This study aims to investigate the replacement of the current 14,1kg aluminium floor with a 40% lighter composite in Nordisk containers. The result of these weight savings are yearly cost reductions or an increased turnover for airliners. I have performed analytical and finite element calculations and have conducted small and full scale tests based on the calculation results and requirements. The tests show that the composites do not have sufficient stiffness which caused excessive deflections in the full scale roller tests. Severe wear on the underside of the composite plates made operation impossible after 800 cycles compared to the aluminium 13000 cycles. Analytical calculations show that decreasing the requested weight savings to 30% might be necessary. For a sufficient stiffness, a composite weight of 9,6kg is achievable.Aerospace EngineeringAerospace Structures & Material
Increasing the Strength of an Adhesive Joint: Geometry Optimization of Complex Joint Configurations for Implementation in Composite Micro Truss Structures
No full textA FEM-based tool was developed for optimization of the geometry of an adhesive joint for implementation in a composite micro truss structure. A genetic algorithm was employed to optimize the adhesive fillet and adherend local end geometry towards a uniform state of strain in the adhesive layer. It was found that the peak maximum principal strain in the adhesive has been reduced up to 36.8 %. However, it was concluded that the optimized joint configurations are unfeasible for implementation in composite micro truss structures as the joint efficiency was estimated to be below 1.0 %.Aerospace EngineeringAerospace Structures & MaterialsStructural Integrity & Composit
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