145,604 research outputs found

    First-Principles Studies of Structure-Property Relationships: Enabling Design of Functional Materials

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    First-principles calculations based on quantum mechanics have been proved to be powerful for accurately regenerating experimental results, uncovering underlying myths of experimental phenomena, and accelerating the design of innovative materials. This work has been motivated by the demand to design next-generation thermionic emitting cathodes and techniques to allow for synthesis of photo-responsive polymers on complex surfaces with controlled thickness and patterns. For Os-coated tungsten thermionic dispenser cathodes, we used first-principles methods to explore the bulk and surface properties of W-Os alloys in order to explain the previously observed experimental phenomena that thermionic emission varies significantly with W-Os alloy composition. Meanwhile, we have developed a new quantum mechanical approach to quantitatively predict the thermionic emission current density from materials perspective without any semi-empirical approximations or complicated analytical models, which leads to better understanding of thermionic emission mechanism. The methods from this work could be used to accelerate the design of next-generation thermionic cathodes. For photo- responsive materials, we designed a novel type of azobenzene-containing monomer for light-mediated ring-opening metathesis polymerization (ROMP) toward the fabrication of patterned, photo-responsive polymers by controlling ring strain energy (RSE) of the monomer that drives ROMP. This allows for unprecedented remote, noninvasive, instantaneous spatial and temporal control of photo-responsive polymer deposition on complex surfaces.This work on the above two different materials systems showed the power of quantum mechanical calculations on predicting, understanding and discovering the structures and properties of both known and unknown materials in a fast, efficient and reliable way

    Quantifying Changes in Creativity: Findings from an Engineering Course on the Design of Complex and Origami Structures

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    Engineering educators have increasingly sought strategies for integrating the arts into their curricula. The primary objective of this integration varies, but one common objective is to improve students’ creative thinking skills. In this paper, we sought to quantify changes in student creativity that resulted from participation in a mechanical engineering course targeted at integrating engineering, technology, and the arts. The course was team taught by instructors from mechanical engineering and art. The art instructor introduced origami principles and techniques as a means for students to optimize engineering structures. Through a course project, engineering student teams interacted with art students to perform structural analysis on an origami-based art installation, which was the capstone project of the art instructor’s undergraduate origami course. Three engineering student teams extended this course project to collaborate with the art students in the final design and physical installation. To evaluate changes in student creativity, we used two instruments: a revised version of the Reisman Diagnostic Creativity Assessment (RDCA) and the Innovative Behavior Scales. Initially, the survey contained 12 constructs, but three were removed due to poor internal consistency reliability: Extrinsic Motivation; Intrinsic Motivation; and Tolerance of Ambiguity. The nine remaining constructs used for comparison herein included: • Originality: Confidence in developing original, innovative ideas • Ideation: Confidence in generating many ideas • Risk Taking: Adventurous; Brave • Openness of Process: Engaging various potentialities and resisting closure • Iterative Processing: Willingness to iterate on one’s solution • Questioning: Tendency to ask lots of questions • Experimenting/exploring: Tendency to physically or mentally take things apart • Idea networking: Tendency to engage with diverse others in communicative acts • Observing: Tendency to observe the surrounding world By conducting a series of paired t-tests to ascertain if pre and post-course responses were significantly different on the above constructs, we found five significant changes. In order of significance, these included Idea Networking; Questioning; Observing; Originality; and Ideation. To help explain these findings, and to identify how this course may be improved in subsequent offerings, the discussion includes the triangulation of these findings in light of teaching observations, responses from a mid-semester student focus group session, and informal faculty reflections. We close with questions that we and others ought to address as we strive to integrate engineering, technology, and the arts. We hope that these findings and discussion will guide other scholars and instructors as they explore the impact of art on engineering design learning, and as they seek to evaluate student creativity resulting from courses with similar aims

    To develop a new mineral carbonation process that have a high efficiency in CO2 absorption into industry slag using low energy mechanical milling

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    Increase in the CO2 emission in atmosphere due to the combustion of fossil fuels has caused serious global warming. Electricity generation, tranportation, and industrial waste are the main sectors indentified to contribute to the emission of CO2 in Malaysia. In dealing with this issue, the absorption of CO2 into industrial waste was experimentally studied by the utilization of mechanical grinding method. This research is to aim a development of new mineral carbonation process that has a high efficiency in the capture and storage of CO2 with low energy consumption. In the first stage of this study, the behavior of CO2 absorption on electric arc furnace and ladle furnace slag was studied by low energy mechanical milling It was found that the absorption is occured during milling. CO2 was stored into the slag mainly as CaCO3. Thus this indicates that the CO2 can be stored permanently inside the slag with this method. In the next stage, the effect of dissolution of metal element into water on the behavior of CO2 absorption was investigated by leaching test experiment. It was found that , concentration value of Fe in pure water is higher but in river water the concentration is lower, the dissolve concentration decreased with the increased in the number of the leaching time. Concentration will be increased at the earlier stage before it decreased at final of concentration. This case because the liquid became saturated and cannot be to dissolved. After the pH steeply increased gradually at an early stage of the elution of slag, it slightly decreased. The pH decreased with the increased in the number of elution. The changes of pH in leaching test it seemed to depend on the content of CaO in the slag. For mechanism of CO2 absorption, morphological change of slag were study and the slag were characteried by using XRD, FE-SEM, and EDS

    Effect of waste plaster of Paris on physical and mechanical properties of ceramic pottery body

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    Over the years, millions tonnes of waste plaster of Paris (POP) were generated and disposed in landfills or most of the time was dumped directly into the environment without any treatments, makes it as one of the environmental issues. Therefore, a new alternative is required to convert the wastes POP into useful materials and marketable to minimize the environmental impact. In the early stage, this study focused on the characterization of the raw material used through particle size analysis, thermal analysis, and identification of its purity. Then, the slip casting technique and standard American Society for Test and Materials (ASTM) was respectively used to fabricate and characterize all of the pottery samples. In the second stage, the ceramic pottery body was fabricated using different composition of waste POP, started from 0 wt.% until 12 wt.%. The samples obtained were analysed through viscosity test and its green body was observed. The results showed that the samples with compositions of 0 to 10 wt.% of waste POP were the only samples that can be used in this study. The analysis on the effects of particle sizes ranging from 25 to 73 μm and sintering temperatures ranging from 950 to 1050 °C on the physical and mechanical properties of the fabricated ceramic pottery body, respectively, were then determined in the third and fourth stage of this study. The physical properties were reported in terms of shrinkage, porosity, and density values; whereas, the mechanical properties were reported in terms of the value of modulus of rupture (MOR). The result showed that a dense and a high strength of ceramic pottery can be produced by using a finer size of particle of 25 μm and at a high sintering temperature of 1050 °C, based on the low porosity value, the high density value, MOR and also the controllable value of shrinkage. Therefore, it can be concluded that the waste POP can be successfully used as a filler to enhance the properties of ceramic pottery body

    Effect of waste plaster of Paris on physical and mechanical properties of ceramic pottery body

    Get PDF
    Over the years, millions tonnes of waste plaster of Paris (POP) were generated and disposed in landfills or most of the time was dumped directly into the environment without any treatments, makes it as one of the environmental issues. Therefore, a new alternative is required to convert the wastes POP into useful materials and marketable to minimize the environmental impact. In the early stage, this study focused on the characterization of the raw material used through particle size analysis, thermal analysis, and identification of its purity. Then, the slip casting technique and standard American Society for Test and Materials (ASTM) was respectively used to fabricate and characterize all of the pottery samples. In the second stage, the ceramic pottery body was fabricated using different composition of waste POP, started from 0 wt.% until 12 wt.%. The samples obtained were analysed through viscosity test and its green body was observed. The results showed that the samples with compositions of 0 to 10 wt.% of waste POP were the only samples that can be used in this study. The analysis on the effects of particle sizes ranging from 25 to 73 μm and sintering temperatures ranging from 950 to 1050 °C on the physical and mechanical properties of the fabricated ceramic pottery body, respectively, were then determined in the third and fourth stage of this study. The physical properties were reported in terms of shrinkage, porosity, and density values; whereas, the mechanical properties were reported in terms of the value of modulus of rupture (MOR). The result showed that a dense and a high strength of ceramic pottery can be produced by using a finer size of particle of 25 μm and at a high sintering temperature of 1050 °C, based on the low porosity value, the high density value, MOR and also the controllable value of shrinkage. Therefore, it can be concluded that the waste POP can be successfully used as a filler to enhance the properties of ceramic pottery body

    Introduction to TIPS: a theory for creative design

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    A highly intriguing problem in combining artificial intelligence and engineering design is automation of the creative and innovative phases of the design process. This paper gives a brief introduction to the theory of inventive problem solving (TIPS) selected as a theoretical basis of the authors' research efforts in this field. The research is conducted in the Stevin Project of the Knowledge-Based System Group of the University of Twente (Enschede, The Netherlands) in cooperation with the Invention Machine Laboratory (Minsk, Belarus). This collaboration aims at developing a formal basis for the creation of an automated reasoning system to support creative engineering design

    Design: One, but in different forms

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    This overview paper defends an augmented cognitively oriented generic-design hypothesis: there are both significant similarities between the design activities implemented in different situations and crucial differences between these and other cognitive activities; yet, characteristics of a design situation (related to the design process, the designers, and the artefact) introduce specificities in the corresponding cognitive activities and structures that are used, and in the resulting designs. We thus augment the classical generic-design hypothesis with that of different forms of designing. We review the data available in the cognitive design research literature and propose a series of candidates underlying such forms of design, outlining a number of directions requiring further elaboration

    Modeling the Structure and Complexity of Engineering Routine Design Problems

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    This paper proposes a model to structure routine design problems as well as a model of its design complexity. The idea is that having a proper model of the structure of such problems enables understanding its complexity, and likewise, a proper understanding of its complexity enables the development of systematic approaches to solve them. The end goal is to develop computer systems capable of taking over routine design tasks based on generic and systematic solving approaches. It is proposed to structure routine design in three main states: problem class, problem instance, and problem solution. Design complexity is related to the degree of uncertainty in knowing how to move a design problem from one state to another. Axiomatic Design Theory is used as reference for understanding complexity in routine design

    Photoelastic Stress Analysis

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