454 research outputs found

    Improvements to the single screw extruder

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    The extrusion on a single screw extruder is examined. The process is divided into several steps: the dosage of the materials to be conveyed; the modification of the shape of the feeding opening which influences the feeding process and consequently the throughput of the extruder; optimizing the shape of the feeding zone to meet the specific material requirements; and plasticizing and homogenizing

    A Pilot Program For The Recruitment and Education of Navy Veterans Based on System-Level Technical Expertise and Leadership Maturation Developed During Service

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    The project, Stern2STEM, aims to advance STEM (Science, Technology, Engineering, and Mathematics) education through the preparation of student veterans to pursue baccalaureate STEM degrees and support the re-employment of these veterans into the Department of Defense (DoD) and the wider defense support industry. The program builds on the training that veterans have received in highly skilled technical areas, both in the classroom and “on-the-job”, to develop system level expertise in their respective technical disciplines. Key components of the program include: (1) establishing a mechanism for outreach and recruitment; (2) providing leveling, tutoring, mentoring, and support for students; (3) teaching and learning through proven pedagogical practices and through sound academic advising; (4) partnering with the DoD community to facilitate student career placement in the DoD STEM workforce; (5) providing workforce development for DoD STEM professionals. This paper will discuss the academic challenges that student veterans face while in higher education and the current STEM pipelines as students move through their college to professional careers. The early impact of academic tutoring, professional advising, mentorship, career placement, and recruitment of current service members into STEM disciplines through involvement with Stern2STEM will be discussed. Through Stern2STEM’s systematic interventions, the project has the potential to have a significant impact on the broader STEM education community as many of the principles, lessons learned, and tools developed will prove valuable for institutions which have a large population of student veterans

    Overview of Game and Content Design for a Mobile Game that Will Prepare Students in Calculus and Physics Prerequisites to the Engineering Curriculum

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    As part of a research project which assists veterans as they exit the military, complete engineering degrees, and enter the workforce as engineering professionals, a range of serious games for Science, Technology, Engineering, and Mathematics (STEM) education is under development. The current focus of this development is CAPTIVATE, a serious game to assist student veterans in mastering the calculus and physics skills that are necessary prerequisites to the main engineering curriculum. Building on the development and lessons learned from MAVEN, a game developed previously to help student veterans master precalculus skills, the design and initial implementation for CAPTIVATE involves careful consideration regarding game and instructional design. Many of the positive aspects from the design of MAVEN will be implemented in CAPTIVATE. First, the overall framework developed for MAVEN will be reused in CAPTIVATE. This modular framework involves both a model and process that combine game, instructional, and software design in a way that supports adaptability throughout the design and development cycle. Additionally by embedding concepts in game play similar to well-known board games such as Battleship, computer games such as Minesweeper, and console or mobile games such as Guitar Hero, students will use their calculus and physics skills to complete tasks in a familiar environment. In addition, the game itself will consist of a series of sub-games each focusing on a topic that students traditionally struggle to understand. Furthermore, students will be offered access to learning resources and assessed regularly as they progress through the game. CAPTIVATE will also overcome some shortcomings from the previous development. While MAVEN was developed for desktop deployment, CAPTIVATE is targeted for deployment on a variety of mobile device including Apple and Android phones and tablets to engage students in interactive games that support their endeavor to build a solid foundation in mathematics and science topics. Additionally by creating games that are short and easily accessible, students will be able to engage with the material at a time and place convenient for them. The development of CAPTIVATE supports student veterans as they transition from the military to engineering degree programs and helps to accelerate them through their STEM prerequisite courses

    Lifting paddle wheel : full-size protype craft development.

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    This report describes the construction, testing and analysis of a large scale lifting paddlewheel craft. No large scale vehicle of this style exists to date; a small scale version has previously been successful. A 4wd farm bike provided the basis for the prototype with modifications for use in an aquatic environment. Following open water tests, ongoing developmental work was carried out. This included the analysis and prediction of the crafts performance, operation of the lifting paddlewheels and comparison of the successful small scale craft to that of the prototype constructed. The prototype did not operate as the lifting paddlewheels were intended. Predictions initially showed a deficit in power comparable with the craft comparison which showed a large difference in the power to weight of the crafts. Modifications to increase the power and following tests proved to also be unproductive. Analysis of the farm bike prototype dynamics showed a possibility of successful operation should certain criteria be met

    LAS BATALLAS FESTIVAS DE ESPANA

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    Serving individual customer needs at reasonable prices can be a profitable target market in high-wage countries. The dilemma between scale and scope-oriented production is one major research topic within the Cluster of Excellence "Integrative Production Technology for High-Wage Countries" at the RWTH Aachen University. One main objective of this project is to bridge the existing gap between individual manufacturing and mass production. Modularization is a widely accepted approach in tool-based manufacturing processes. In this paper, we propose a flexible design methodology for modular tools and dies. The methodology will assist the design engineer in setting up a series of modularized tools in a conceptually closed manner. The described methodology covers modularization in a broad sense, i.e. it includes hardware modularization as well as modularization of the construction process. The methodology consists of three phases: initiation, analysis and design phase

    Nernst effect as a probe of superconducting fluctuations in disordered thin films

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    In amorphous superconducting thin films of Nb0.15Si0.85Nb_{0.15}Si_{0.85} and InOxInO_x, a finite Nernst coefficient can be detected in a wide range of temperature and magnetic field. Due to the negligible contribution of normal quasi-particles, superconducting fluctuations easily dominate the Nernst response in the entire range of study. In the vicinity of the critical temperature and in the zero-field limit, the magnitude of the signal is in quantitative agreement with what is theoretically expected for the Gaussian fluctuations of the superconducting order parameter. Even at higher temperatures and finite magnetic field, the Nernst coefficient is set by the size of superconducting fluctuations. The Nernst coefficient emerges as a direct probe of the ghost critical field, the normal-state mirror of the upper critical field. Moreover, upon leaving the normal state with fluctuating Cooper pairs, we show that the temperature evolution of the Nernst coefficient is different whether the system enters a vortex solid, a vortex liquid or a phase-fluctuating superconducting regime.Comment: Submitted to New. J. Phys. for a focus issue on "Superconductors with Exotic Symmetries

    Pilot Programs for Veterans Transition To Engineering Fields

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    Veterans, through their active service, frequently receive training in highly skilled technical areas. However, they may lack a theoretical background in underlying engineering principles. They also need additional support with the transition from a highly structured military environment to an environment with more ambiguous time constraints and different sorts of responsibilities. Moreover they are facing challenges which are specific for their student population. Therefore, enabling multiple mechanisms which would support them and provide them necessary guidance are especially important at universities with large veteran populations such as at Old Dominion University in Norfolk, Virginia. Hence, there is a need for programs which build on the specialized training that veterans received and aid in their academic journey. This paper will introduce three pilot programs for advancing engineering education for military veterans focusing on forming a support base for veterans to assist them in overcoming traditional educational barriers

    Исследование остаточных углеводородов в ходе деструкции гептана углеводородокисляющими микроорганизмами рода Pseudomonas и Rodococcus

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    Molding of micro structures by injection molding leads to special requirements for the molds e.g. regarding wear resistance and low release forces of the molded components. At the same time it is not allowed to affect the replication precision. Physical vapor deposition (PVD) is one of the promising technologies for applying coatings with adapted properties like high hardness, low roughness, low Young's modulus and less adhesion to the melt of polymers. Physical vapor deposition technology allows the deposition of thin films on micro structures. Therefore, the influence of these PVD layers on the contour accuracy of the replicated micro structures has to be investigated. For this purpose injection mold inserts were laser structured with micro structures of different sizes and afterwards coated with two different coatings, which were deposited by a magnetron sputter ion plating PVD technology. After deposition, the coatings were analyzed by techniques regarding hardness, Young's modulus and morphology. The geometries of the micro structures were analyzed by scanning electron microscopy before and after coating. Afterwards, the coated mold inserts were used for injection molding experiments. During the injection molding process, a conventional and a variothermal temperature control of the molds were used. The molded parts were analyzed regarding roughness, structure height and structure width by means of laser microscopy
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