1,720,976 research outputs found
Studies of enzymes involved in the primary and secondary metabolism of antibiotic producing Streptomyces
No full textSIGLEAvailable from British Library Document Supply Centre- DSC:DX172121 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Development of an innovative seismic design procedure for frame-wall structures
No full textA displacement-based design (DBD) methodology for structures that are comprised of both frames and walls has been proposed and then tested through examination of several case studies. Strength proportions between walls and frames are decided before any analysis has begun. The various steps required to represent a frame-wall structure as a single-degree of freedom system are identified and a Direct DBD process is then adopted to set the required strength level. To test the design methodology, two sets of 4, 8, 12, 16 and 20-storey reinforced concrete structures are designed, with different proportions of the total strength assigned to the frames. A suite of time-history analyses have then been conducted to validate the methodology, which is seen to perform reasonably well. Finally, improvements to the procedure are outlined and areas for future research are identified
A model code for the displacement-based seismic design of structures, DBD12
No full textThis publication has been developed to provide guidance as to how the direct displacement-based design methodology can be codified. It is intended for insertion within the seismic requirements of a code, establishing how design forces can be obtained using a Direct Displacement-Based Design (DDBD) approach. The document has currently been prepared with reference to several clauses of Eurocode 8. This document is presented in a traditional “Code + Commentary” format, on a split two-column page. The commentary aims to generally clarify the code requirements and indicate references where the background and further discussion on the requirements can be found
Effectiveness of simple approaches in mitigating residual deformations in buildings
No full textDevelopments in performance-based seismic design and assessment approaches have emphasized the importance of considering residual deformations. Recent investigations have also led to a proposed direct displacement-based design (DDBD) approach which includes an explicit consideration of the expected residual deformations as an integral part of the design process. Having estimated the expected residual deformations in a structure, engineers are faced with the problem of reducing them to meet the targeted performance levels under pre-defined seismic hazard levels. Previous studies have identified the post-yield stiffness as a primary factor influencing the magnitude of residual deformations in single degree of freedom and multiple degree of freedom structures. In this paper, a series of simple approaches to increase the post-yield stiffness of traditional framed and braced systems for the purpose of reducing residual deformations are investigated. These methods do not utilize recentring post-tensioned technology. This contribution addresses the feasibility of altering the lateral post-yield stiffness of structural systems by: (i) using different reinforcement materials with beneficial features in their stress-strain behaviour; (ii) re-designing the section geometry and properties of primary seismic-resisting elements; and (iii) introducing a secondary elastic frame to act in parallel with the primary system. The efficiency of each of these techniques is investigated through monotonic and cyclic moment-curvature and non-linear time-history analyses. Of these approaches the design and introduction of an elastic secondary system was found to be most effective and consistent in reducing residual deformations. A simplilfied design approach for achieving the desired increase of a system's post-yield stiffness is also presented. Copyright © 2007 John Wiley & Sons, Ltd
Performance-Based Issues from the 22 February 2011 Christchurch Earthquake
No full textAt 12:51 pm local time on 22 February 2011, a Mw 6.2 aftershock of the September 4, 2010, Darfield Earthquake shook the city of Christchurch, New Zealand. The aftershock occurred on an unmapped fault less than 8 km from the city center resulting in the collapse of two reinforced concrete office buildings and one concrete parking garage, and severe damage to numerous others. The region has continued to suffer from aftershocks and further damage to building structures throughout the year following the February earthquake. This paper summarizes the observed damage to buildings in the Central Business District (CBD), with a specific focus on identifying future research to support the development of performance-based design procedures. © Springer Science+Business Media Dordrecht 2014
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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