Structures Research Papers - Academia.edu (original) (raw)

The chemical structure of the milled-wood lignin isolated from Paulownia fortunei wood was investigated. The lignins were characterized by analytical pyrolysis and two-dimensional NMR that indicated a predominance of guaiacyl (G) over... more

The chemical structure of the milled-wood lignin isolated from Paulownia fortunei wood was investigated. The lignins were characterized by analytical pyrolysis and two-dimensional NMR that indicated a predominance of guaiacyl (G) over syringyl (S) units, and only showed small amounts of p-hydroxyphenyl (H) units, with a H:G:S molar ratio of 1:59:40. The heteronuclear single quantum correlation (HSQC) NMR spectrum gave additional information about the relative abundances of the different inter-unit linkages present in the lignin structure. Paulownia lignin showed a predominance of -O-4� aryl ether linkages (62% of total side-chains), followed by � resinol-type (12%) and -5 � phenylcoumaran-type structures (11%) and with lower amounts of other condensed structures such as spirodienone (3%) and dibenzodioxocin (2%) structures. The high lignin content (ca. 23% Klason lignin), together with the low S/G ratio and the abundance of condensed (carbon–carbon linked) structures (together with ...

: This research aims to develop, analyze, and evaluate a new type of structural element that will enhance the crashworthiness of naval vehicles by providing outstanding energy absorption with minimal weight. The structural element is an... more

: This research aims to develop, analyze, and evaluate a new type of structural element that will enhance the crashworthiness of naval vehicles by providing outstanding energy absorption with minimal weight. The structural element is an array of concentric fiber reinforced composite tubes with extension-twist coupling and ultra-high Poisson's ratio. The tubes are configured to crush or shear internal foam as a means of absorbing energy. This interim report includes technical progress, plans, publications, and various administrative matters. In the current period, work has focused on evaluating the mechanisms of energy absorption in composite tubular structures and the development of analytical models for predicting the deformation and damage in these tubular structures. A significant effort was dedicated towards developing the manufacturing and testing technology for tubes having extension-twist coupling. This effort culminated in the successful demonstration, for the first time...

Current seismic design philosophy used worldwide tolerates a degree of damage at locations predefined by the designer, as long as a complete structural collapse is precluded. By accepting plastic deformations, the maximum acceptable... more

Current seismic design philosophy used worldwide
tolerates a degree of damage at locations predefined by the
designer, as long as a complete structural collapse is precluded.
By accepting plastic deformations, the maximum acceptable
forces can be controlled and construction costs can be reduced.
Major earthquakes, e.g. the Canterbury earthquakes, showed
that well-designed structures behave as anticipated. The joints
suffered plastic deformation as the designer intended, while the
occupants remained alive. Repair costs, however, were often
high. Costs also accrue because, post-earthquake, the
infrastructure is no longer fit for purpose. These costs are very
difficult to predict.
Low-damage seismic design, in contrast, can be achieved
by activating rigid-like body movement of structural members.
Development of forces resulting from structural local
deformation can then be prevented. Consequently, associated
damage to structural members can be avoided. Recent research
outcomes at the University of Auckland Centre for Earthquake
Engineering Research will be presented.

The last fifteen years have witnessed an explosion in the popularity, creativity, and productiveness of economic sociology, an approach that traces its roots back to Max Weber. This important new text offers a comprehensive and up-to-date... more

The last fifteen years have witnessed an explosion in the popularity, creativity, and productiveness of economic sociology, an approach that traces its roots back to Max Weber. This important new text offers a comprehensive and up-to-date overview of economic sociology. It also advances the field theoretically by highlighting, in one analysis, the crucial economic roles of both interests and social relations. Richard Swedberg describes the field's critical insights into economic life, giving particular attention to the effects of culture on economic phenomena and the ways that economic actions are embedded in social structures. He examines the full range of economic institutions and explicates the relationship of the economy to politics, law, culture, and gender. Swedberg notes that sociologists too often fail to properly emphasize the role that self-interested behavior plays in economic decisions, while economists frequently underestimate the importance of social relations. Th...

The benefits of Hyperion hyperspectral data to agriculture have been studied at sites in the Coleambally Irrigation Area of Australia. Hyperion can provide effective measures of agricultural performance through the use of established... more

The benefits of Hyperion hyperspectral data to agriculture have been studied at sites in the Coleambally Irrigation Area of Australia. Hyperion can provide effective measures of agricultural performance through the use of established spectral indexes if systematic and random noise is managed. The noise management strategy includes recognition of "bad" pixels, reducing the effects of vertical striping, and compensation for

This paper attempts to quantify the impact of the COVID-19 pandemic on the construction industry under different investment and economic scenarios in Egypt. The survey was conducted to assess the cost impact of the ongoing COVID-19... more

This paper attempts to quantify the impact of the COVID-19 pandemic on the construction industry under different investment and economic scenarios in Egypt. The survey was conducted to assess the cost impact of the ongoing COVID-19 pandemic on the construction industry, considering essential aspects, such as manpower, plant and machinery, and material, and their net effect on overall construction cost. The recommendations covered in this paper address many such measures under short, medium, and long-term categories. These measures underline the need to improve systems and processes for adequately responding to the current changing environment and effectively confronting such disruptions in the future. In addition, the paper serves as a start to thinking about the study of procedures during a future pandemic to inhibit any impact on the project timeline or personnel health.

Design of seismic-resistant civil structural systems necessitates a balanced minimization of two general conflicting objective functions: the short-term construction investment and the long-term seismic risk. Many of the existing seismic... more

Design of seismic-resistant civil structural systems necessitates a balanced minimization of two general conflicting objective functions: the short-term construction investment and the long-term seismic risk. Many of the existing seismic design optimization procedures use single objectives of either the traditional minimum material usage (weight or cost) or the recent minimum expected life-cycle cost, while imposing constraints from relevant code specifications as well as additional seismic performance requirements. The resulting single optimized structural design may not always perform satisfactorily in terms of other important but competing merit objectives; the designer's individual risk-taking preference is not explicitly integrated into the design process. This paper presents a practical and general framework for design optimization of code-compliant seismic-resistant structures. Multiple objective functions, which reflect material usage, initial construction expenses, degr...

Abstract According to the basic concept of seismic isolation, the base-isolated structures must remain elastic during an earthquake. On the one hand, the existing technical documentation and codes strongly noted that the superstructure of... more

Abstract According to the basic concept of seismic isolation, the base-isolated structures must remain elastic during an earthquake. On the one hand, the existing technical documentation and codes strongly noted that the superstructure of isolated buildings should be designed the same as a fixed base structure. The only difference is the isolator. So, its period is higher, and consequently the applied acceleration is lower. One of the criteria for designing fixed-base structures is a seismic design and especially compact transverse rebars for beams and columns near the support. In the present study, 12 structures of 8 to 24 stories were designed in both fixed and isolated forms. Then, a program was written in MATLAB that calculated “moment-curvature” and “P-Mx-My interaction” curves for concrete beam and column sections with any amount of transverse rebars (Av/s). Having these curves, the structures were push-over analyzed in three sway conditions “ordinary”, “intermediate” and “special”. The results also showed that, unlike fixed-base structures, the response modification factor (Ru) of the isolated structures was not affected by the seismic design level of beams and columns. Also, in the two “target” and “final” displacements, the number of plastic hinges formed in IO or thereafter, in the isolated structures was much less than the fixed ones.

his thesis aims to provide general insight into form-finding and structural analysis of bending-active structures. The work is based on a case study approach, in which findings from prototypes and commercial building structures become the... more

his thesis aims to provide general insight into form-finding and structural analysis of bending-active structures. The work is based on a case study approach, in which findings from prototypes and commercial building structures become the basis for generalised theoretical investigations. Information is continuously fed back from these case study structures into theoretical research, which creates the basis for overall working methods. The behaviour of five investigated structures is found to be independent of clearly predictable load bearing categories. Their load bearing mechanisms are largely dependent on the boundless variety of topologies and geometrical expressions that may be generated. The work therefore understands active bending as an approach to generating new structural forms, in which common load bearing behaviour is found due to the structures inherently large elasticity and inner stress state. Based on engineering and historical background, methodological, mechanical a...

The lithic evidence from some 20 churches shows that the flying buttress was first used in the 1150s, immediately after the Second Crusade. This reflected a new way of thinking about structures that had been stimulated in the first place... more

The lithic evidence from some 20 churches shows that the flying buttress was first used in the 1150s, immediately after the Second Crusade. This reflected a new way of thinking about structures that had been stimulated in the first place by the rib - a view from seeing the building as mass to seeing it as a collection of axes, or as lines of stress. This was the first time in history that masonry had been conceived as if it were timber.

Île Barbe is located on the Saône, around ten kilometers to the north of Lyon. It was the object of several archaeological test operations in 2011. The Sainte-Anne property is located on the eastern point of the Île. Its restoration... more

Île Barbe is located on the Saône, around ten kilometers to the north of Lyon. It was the object of several archaeological test
operations in 2011. The Sainte-Anne property is located on the eastern point of the Île. Its restoration included the repair of all the
exterior coatings, as well as diverse exterior and interior modifications, thus requiring a preventive excavation associating a study of the
built structures and supervision of the construction work. In this context, one of the trenches yielded a Final Bronze Age occupation
level. The latter, already suspected during the test phase (Vicard et alii, 2011 ; Gaillard et alii, 2012), was this time characterized
by the presence of diverse features (ovens, rubified sediments, postholes, thin sediment layers, etc.) associated with well-preserved metal
and ceramic artifacts. Two small manually dug test-pits show that the Protohistoric level is more than one meter deep (the bedrock has
not been reached), and that the level dated to the Final Bronze Age overlies an equivalent level that yielded artifacts attributed to the Final Neolithic. At the bottom of the latter, a new sedimentary unit yielded ceramic artifacts typical of the Middle Neolithic. Though
the interpretation of these unexpected discoveries is still incomplete, the latter make this site exceptional in terms of its configuration
and preservation conditions, until now rarely encountered in the Lyon region.

The purpose of this paper was to highlight points that are necessary to bridge the gaps, where they exist, in relation to the structures, process and outcome of nursing education when compared with those of other professions. As a... more

The purpose of this paper was to highlight points that are necessary to bridge the gaps, where they exist, in relation to the structures, process and outcome of nursing education when compared with those of other professions. As a profession, nursing is broad in scope, and nurse practitioners are expected to possess a body of knowledge and skills for dependent, independent and inter-dependent practice. In many professions, preparation usually takes place in Colleges or University settings and educational preparation is usually prolonged to include instructions in the specialized body of knowledge and techniques of the profession. However, nursing education globally is highly variable, taking place in a myriad of programmes at the hospitals, technical institutes and institutions of higher learning with no uniformity. Furthermore, regarding educational outcome, many nurses in recent years are unable to meet the entry level competencies for registered nurses/midwives prior to employmen...

The man-made water retaining structures at the Folsom Dam and Reservoir Project, located on the American River about 20 miles upstream of the city of Sacramento, California, have been evaluated for their seismic safety in the event of a... more

The man-made water retaining structures at the Folsom Dam and Reservoir Project, located on the American River about 20 miles upstream of the city of Sacramento, California, have been evaluated for their seismic safety in the event of a Magnitude 6.5 earthquake occurring on the East Branch of the Bear Mountains fault zone at a distance of about 15 km. This report documents the study of the Right and Left Wing Dams, two of the zoned embarkment dams at the Folsom Project. The evaluation process involved extensive review of construction records, field and laboratory investigations, and analytical studies. It has been determined that the Right and Left Wing Dams will perform satisfactorily during the design earthquake.