196,026 research outputs found
Adaptive bending-active modules for a tensile solar shading system
No full textAdaptive façades can be a solution to many urban aspects such as sustainability and energy efficiency. Along these lines, a parametric analysis has been conducted to investigate the geometrical reconfigurations of the proposed adaptive solar shading system, the daylight performance with Rhinoceros and the plugins Grasshopper and ClimateStudio as well as the structural behaviour with Karamba3D. A skeleton structure synthesized by GFRP bending-active elements and stabilized by a secondary system of cables with variable length and a PTFE tensile skin leads to a lightweight modular structure with embedded actuation. The control system is capable of flexible patterns and multi-stages of open, semi and close configurations for different sun shading effects, depending on the changeable weather conditions and the relative response required in every part of the façade. The mechanism recalls a Class-2 Tensegrity system with springed hinges, where the rigid members and the hinges are substituted by lamellas, which can be bend by controlling the length of the cables. Furthermore, the ever-changing modular structure, especially to the plethora of different configurations, results in an aesthetically pleasing and organic dynamic filter for a tall building. Further research can be carried out about the wind load, how the structure can be naturally wind-resistant, and convective factors triggered by air movements between the façade and the building itself
Adaptive tensegrity structures for dynamic facades of energy efficient buildings
No full textThe use of tensegrity structures for the construction of active solar façades of Energy Efficient Buildings (EEBs) has been investigated in recent studies. The present work moves along such lines by proposing a methodology that supports the development of the design and construction process of new façade components with tensegrity architecture. The activation motion of the examined tensegrity façade system mimics the dynamics of a blinking sail. The use of the proposed façade system as a dynamic sun-screen harvesting device is presented, with the aim of illustrating the application of tensegrity architectures to the design of next-generation dynamic solar façades of EEBs. Finally, some considerations are presented on adaptive envelope systems and their direct implementation on the building façade
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Transformabilidad en las estructuras adaptativas de Frei Otto y más allá
No full text[EN] Adaptive structures can conform to external changing conditions, in order to improve their functional, energy related and/or load-bearing behavior. Structural adaptation can be depicted in the work of Frei Otto on lightweight tensile structures and elastic gridshells of reduced structural mass and materials with high strength and relatively low elastic modulus respectively. The main developments achieved were based on transformability in the structural simulation and erection process. Representative examples include the Olympic Stadium in Munich in 1972 and the Mannheim Multihalle in 1975 respectively. With the rise of digital and numerical technology in the last 20 years, Frei Otto s ideas and concepts are even more important and relevant today than they were half a century ago when they first emerged. Meanwhile, research and development of actual adaptive structures are based on the afore-mentioned principles of form variation and lightweight, as well as on aspects of flexibility, controllability and simplicity in kinematics. In achieving this, the development of adaptive structures with minimum embedded actuation and maximum possible output structural states, gains significance. Selected prototype developments demonstrate related achievements in the area.[ES] Las estructuras adaptativas pueden adaptarse a condiciones externas cambiantes para mejorar su comportamiento funcional, energético y/o de carga. La adaptación estructural puede representarse en los trabajos de Frei Otto sobre estructuras ligeras de tracción y cáscaras de rejilla elásticas de masa estructural reducida y materiales de alta resistencia y módulo elástico relativamente bajo, respectivamente. Los principales avances logrados se basaron en la transformabilidad en el proceso de simulación y montaje estructural. Algunos ejemplos representativos son el Estadio Olímpico de Múnich en 1972 y el Multihalle de Mannheim en 1975, respectivamente. Con el auge de la tecnología digital y numérica en los últimos 20 años, las ideas y conceptos de Frei Otto son aún más importantes y relevantes hoy que hace medio siglo, cuando surgieron por primera vez. Mientras tanto, la investigación y el desarrollo de estructuras adaptativas reales se basan en los principios antes mencionados de variación de forma y ligereza, así como en aspectos de flexibilidad, controlabilidad y simplicidad en la cinemática. Para lograrlo, cobra importancia el desarrollo de estructuras adaptables con un mínimo de actuación incorporada y un máximo de estados estructurales de salida posibles. Una selección de prototipos demuestra los logros alcanzados en este campo.C. Phocas, M.; Matheou, M. (2024). Transformability in adaptive structures of Frei Otto and beyond. VLC arquitectura. Research Journal. 11(2):237-249. https://doi.org/10.4995/vlc.2024.21914OJS23724911
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Large-Eddy Simulations of Molecular Mixing in a Recirculating Shear Flow
No full textThe flow field and mixing in an expansion-ramp geometry is studied using large-eddy simulation (LES) with subgrid scale (SGS) modeling based on the stretched-vortex model. The expansionramp geometry was developed to provide enhanced mixing and flameholding characteristics while maintaining low total-pressure losses, elements that are important in the design and performance of combustors for hypersonic air-breathing propulsion applications. The mixing was studied by tracking a passive scalar without taking into account the effects of chemical reactions and heat release.
In order to verify the solver and the boundary closure implementation, a method utilizing results from linear stability analysis (LSA) theory is developed. LSA can be used to compute unstable perturbations to a flow, subject to certain approximations. The perturbations computed from LSA are used as an inflow condition to the flow computed by the solver been assessed. A projection based metric is constructed that only assumes the shape of the solution and not the growth rate of the perturbations, thus also allowing the latter to be determined as part of the verification. The growth rate of the perturbations for an unbounded (effectively) incompressible shear layer and a confined compressible shear layer is found to be in agreement with the prediction of the LSA.
The flow and mixing predictions of the LES are in good agreement with experimental measurements. Total (resolved and subgrid) probability density functions (PDFs) of the passive scalar are estimated using an assumed beta-distribution model for the subgrid scalar field. The improved mixing characteristics of the expansion-ramp geometry compared to free shear layers are illustrated by the shapes of the PDFs. Moreover, the temperature rise and the probability of mixed fluid profiles are in good agreement with the experimental measurements, indicating that the mixing on a molecular scale is correctly predicted by the LES–SGS model. Finally, the predictions of the LES are shown to be resolution-independent. The mean fields and passive scalar PDFs have essentially converged at the two finer grid-resolutions used.</p
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
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