292 research outputs found
Engineering excellence at Rolls-Royce; a taste of English culture
No full textRolls-Royce is one of the most well-known brands in the world and synonymous with the highest engineering quality. Amongst Aerospace Engineers, Rolls-Royce is directly associated with the Trent turbofan aircraft engines. The engines power the world’s newest passenger aircraft, including the Boeing 787 Dreamliner and the large Airbus A380. A Rolls-Royce powered aircraft takes o! or lands every 2.5 seconds.Aerospace Engineerin
Beloved Community: Martin Luther King, Howard Thurman, and Josiah Royce
No full textMartin Luther Kings primary emphasis was upon beloved community, a phrase he borrowed from Royce, but an idea that he shared with St. Augustine. Theories of the state tend to focus upon division, in which one stratum dominates another or others. Kings context is the US in the segregated Southa region whose internal divisions sharply instantiate the idea of the state as an unequal hierarchy of dominance. Kings appeal was less to end black subjugation than to end subjugation as such. Hence King was called by some a dreamer, given his background commitment to equality and community, ideals taking marginal precedence over his foreground commitment to liberty and autonomy. This article explores the notion of beloved community broadly and then specifically in Martin Luther King along with related notions in Howard Thurman (1900-1981) and in Josiah Royce (1855-1916). KEYWORDS: Martin Luther King, Howard Thurman, Josiah Royce, Beloved Community, Equality, Desegregation, African American Studies, Arts and Humanities, Christianity, Philosophy, Religio
AAC Royce field pea
No full textAAC Royce is a semi-leafless, green cotyledon field pea (Pisum sativum L.) cultivar developed at Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta, Canada. It has maturity of 105 days, thousand seed weight of 254 g, and a medium lodging resistance. AAC Royce is resistant to powdery mildew (caused by Erysiphe pisi Syd.), and moderately susceptible to mycosphaerella blight (caused by Mycosphaerella pinodes) and fusarium wilt (caused by Fusarium oxysporum). AAC Royce is adapted to all field growing regions in western Canada.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Working memory training increases general learning abilities in CD-1 outbred mice:
No full textGeneral intelligence is a cognitive trait that is purported to influence most domain-specific learning abilities in humans. Like humans, CD-1 outbred mice express individual differences in their "general" cognitive abilities, such that performance across diverse batteries of learning tasks tend to be positively correlated, and this general learning factor accounts for 32-48% of the variance of individual animals performance in cognitive test batteries. It has been demonstrated that in both humans and mice, the efficacy of working memory capacity correlates highly with measures of general cognitive ability. In three experiments, here we demonstrate that in genetically heterogeneous mice, repetitive working memory training promotes an increase in selective attention and has a commensurately positive effect on the animals' aggregate performance on a battery of five learning tasks. The enhancement of general cognitive performance by working memory exercise was attenuated if the selective attention demands of that exercise were reduced. Finally, because much of the human research conducted on working memory training is done in pre-pubescent children, we trained a group of mice beginning in pre-pubescence and found no difference between that group and one trained at our typical young-adult age. In total, these results provide initial evidence that the efficacy of working memory capacity and selective attention are causally related to an animal’s general cognitive performance, and suggest behavioral strategies to promote those abilities.Ph.D.Includes bibliographical references (p. 63-65)by Kenneth Royce Ligh
The Mineral Susceptibility Database
No full textThe Mineral Susceptibility Database (MSD) consolidates current relevant research from various fields (including museums, earth science, chemistry, and material science) into one freely accessible location. Its aim is to be a comprehensive reference for museum professionals—and a starting point for further research—when assessing the conditions required by their mineral collections and objects.
The data were collected from January 2019 to May 2021 by reviewing various journal articles and publications for relevant data, which was then synthesised and inserted into the correct fields of the Database. The Database was created and designed in Microsoft Excel. This was exported into a PDF to ensure reliability (by avoiding any 3rd party tampering) and format preservation, and to allow for broader access (as most web browser are capable of reading PDFs).
While the data presented in the MSD is replicated in good faith from trusted sources, it is recommended for one to return to the original source document and confirm parameters with the corresponding author
Infinity and the Self: Royce on Dedekind
No full textInternational audienceIn Die Zahlen (1888), Dedekind defines an infinite set as a set that is isomorphic with one of its proper parts. In The World and the Individual (1900), the American philosopher Josiah Royce relates Dedekind’s notion to Fichte’s and Hegel’s concept of Self defined as an entity that reflects itself into itself. The first aim of this article is to explain Royce’s analysis and to put it in its proper context, that of a critique of Bradley’s mystical idealism. The second aim is to urge a shift in focus in Dedekind’s scholarship: instead of addressing the question of the relationship between mathematics and philosophy in Dedekind’s work through the supposed intentions of its author, it is more fruitful to analyze the reception that philosophers have made of his texts
Design of Continuity Connections for Precast, Pretensioned Girders Using Ultra-High Performance Concrete
No full textIn recent years, an increased desire to improve the durability and resiliency of bridges has become an important consideration in design. Ultra-high performance concrete (UHPC) is a relatively new cementitious composite material with mechanical and durability properties far superior to conventional concrete. UHPC has high compressive and tensile strength, excellent bond strength to adjacent concrete sections, and a relatively short development length for steel reinforcement. Eliminating joints in a bridge deck with continuous spans can improve the durability of the bridge by reducing the number of pathways for water to penetrate to the bridge structure. The practice of designing connections of precast girders made continuous for live load with conventional concrete is well understood and utilized in practice, but little guidance exists on the structural design of continuity connections made of UHPC or the retrofit of simple spans to be made continuous. The desire to use UHPC is apparent because connections made of conventional concrete often crack during service and the superior properties of UHPC can lead to simpler connection details. Cracking can cause a loss of continuity and allow water to degrade both the reinforcing steel and adjacent concrete. The focus of this research was to investigate how embedment length, UHPC materials, and steel reinforcement geometry affect the performance of connections of pretensioned girders made continuous for live load. A total of six 19 ft long test specimens were constructed to represent a two-span continuous prestressed bridge system. The continuity connections were constructed using two types of UHPC material, a locally developed mix design labeled J3 and a commercially available product. Two types of positive moment steel reinforcement details were tested: 10 in. straight strands and 16 in. long hooked strands, which are both formed as extensions of the prestressing strands in the girders. To replicate the loads a bridge system would experience during service, the specimens were tested to induce both a positive and negative moment in the connection. The measured data correlated well with the literature on the bond strength of UHPC and suggested that hooked strands and longer embedment lengths generally lead to increased load carrying capacity. Additionally, the data suggests that the required dimension and embedment lengths for continuity connections made of UHPC could be smaller than conventional concrete
INTERNAL CURING OF CALCIUM SULFOALUMINATE CEMENT CONCRETE USING LIGHTWEIGHT AGGREGATE
No full textCalcium sulfoaluminate (CSA) cement is a very rapid setting, hydraulic cement that releases approximately half as much carbon dioxide during production as conventional portland cement. CSA cement produces concrete with high early strength, excellent durability, and limited shrinkage. This cement also requires approximately twice as much water as conventional portland cement for proper hydration. The introduction of internal curing water from presoaked lightweight aggregate into the mix design allows more time for hydration during the curing process. The additional time for hydration provided by internal curing has the potential for positive effects on the performance of CSA cement concrete. The work described in this thesis examined three CSA cements and portland cement with 0 lb, 5 lb, 7 lb, and 10 lb of internal curing water per 100 lb of cement added to each mix design through the use of presoaked lightweight aggregate. Concrete specimens cast from each mix design were tested for compressive strength, permeability through the Rapid Chloride Ion Permeability test, and length change to measure shrinkage of the concrete. It was determined that the compressive strength of the Buzzi CSA cement concrete was impacted most positively by adding 5 lb of internal curing water. The Komponent® cement concrete exhibited the most improvement in performance from adding internal curing water; it showed an improvement in compressive strength and permeability results and reduced shrinkage. In general, the addition of 7 lb of internal curing water reduced shrinkage for all CSA cements examined. The conventional portland cement was the only cement tested that did not exhibit clear benefits from the addition of internal curing water
Evaluation of Specialized Concretes for the Repair of Damaged Continuity Joints in Prestressed Girder Bridges
No full textPrecast, prestressed concrete simple span girder bridges made continuous through the use of continuity joints exhibit a great, structural advantage when dealing with additional dead and live loading across the deck. Unfortunately, time-dependent effects such as temperature, creep, and shrinkage may cause the girders to camber upward and the continuity joint to crack. The crack in the joint can cause a loss of continuity and leaves the reinforcement within prone to corrosion damage. A potential solution to this problem is to repair the damaged continuity joint using specialized concretes such as ultra-high-performance concrete (UHPC), fiber-reinforced self-consolidating concrete (FR-SCC), and a magnesium aluminum liquid phosphate concrete (MALP), called Phoscrete®. These specialized concretes have been shown to perform better than traditional concrete. An extensive literature review of previous research has been done to gain an understanding of what the current state of continuity joint repair is in and where it should be heading. The main objective of this study was to provide an adequate continuity joint repair solution for in-service bridges showing deterioration from time dependent effects.
This research began by constructing and combining twenty-four half-scale, half-length AASHTO Type II bridge girders resulting in twelve girder-joint-girder specimens. Steel reinforcement within the continuity joint was based on previous research and adapted to the specific sizing of the specimens for this research. The specimens were tested under two different load cases – positive and negative moment bending. Three of the twelve girder-joint-girder specimens acted as the control group and tested to negative moment flexural failure. Observations and data for the load at failure, strain, and deflection were collected. The remaining nine specimens were initially loaded in positive moment bending until a crack began to propagate upward within the continuity joint. This crack simulated girder-joint-girder damage found in the field. Repairs using additional reinforcement and specialized concretes were constructed and tested. Six repair specimens’ moment capacities (two from each repair material) were determined in negative moment bending and three moment capacities (one from each repair material) were determined in positive moment bending. Once again observations and data for the load at failure, strain, and deflection were collected. The results from the tests were compared to the data from the control group and each other. These results indicated viable options for girder-joint-girder repairs in the field
Method of Rehabilitation for Corrosion Damage in The End Region of Prestressed Concrete Bridge Girders
No full textTwo of important factors in longevity of prestressed concrete bridge girder are the effect of corrosion to prestressing reinforcement in concrete and process of stress transferring from prestressing strands to concrete. The process of stress transfer controls the overall quality of structural member in term of providing significant contribution to bridge girder shear capacity. During the process of stress transfer, a bond between prestressing reinforcement and concrete is established by Hoyer’s effect. Prestressed bridges are expected to last approximately 50 years. However, because of the corrosion due to the penetration of chemicals at the end region of the bridge girder, where the process of stress transfer initially occurs, concrete starts spalling and breaks bond between it and prestressing strands. Therefore, the bridge girder loses their shear capacity by time. In some scenarios where shear capacity is slightly affected, the bridge girder can be repaired on site, but replacement of bridge girder is the last option when it is damaged severely.
In this research, the investigation and experiments were conducted to evaluate the feasibility of rehabilitating shear capacity by encapsulating corroded end region with new repair materials as Ultra-High Performance Concrete (UHPC), Fiber-Reinforced Self-Consolidating Concrete (FR-SCC), and Magnesium-Alumino-Liquid Phosphate (MALP) concrete. The purpose of this research does not restore the lost prestressing force at the end region but create large cross-sectional dimensions using high quality materials for retrofitting. The repair materials shall construct a low-permeable or impermeable block around the end region to resist further corrosion occurs. For the research’s experiment, nine half-scale AASHTO Type II girders were constructed with a hollow space, whose dimension was 18 in. x 9 in. x 2 in., at one end of the girder to represent the corroded region. The, the repair materials were cast to encapsulated corroded region and tested to bring out the result of repair’s contribution in rehabilitating the shear strength of girder. The new materials bonded to the conventional concrete well, which pointed out that the integral behavior of composite member was conservative. However, UHPC and FR-SCC increased the girder’s ultimate load capacity while MALP was overestimated as it did not increase the ultimate capacity of the girder as well as other materials. Also, the appearance of the new materials changed the failure mechanism of the girder from bond-shear failure (Mujtaba, 2021) to bond-shear/flexure failure. The outcomes of this research shall provide the Oklahoma Department of Transportation a perspective in comparison of performance between three repair materials, and quality control of each repair materials in use
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