4,610 research outputs found
SOR models and Ethnicity data in LIS and LES : country by country report
This research considers the idea that a single metric expressing distance between social groups may be an adequate tool for investigating the relationship between ethnic/nationality minority group membership and social stratification. A Stereotyped Ordered Regression (SOR) model is proposed as a methodology for deriving this metric 1, and this paper considers the role of SOR models for the variety of countries with appropriate data made available by the Luxembourg Income and Employment studies (LIS and LES). In particular, by making the referents of this metric relatively consistent between different countries, it is suggested that a cross-nationally comparable representation of ethnic/nationality group membership can be derived which reduces the difficulties of international comparative research on ethnicity. Section one of this paper deals with three introductory issues: the clarification of the proposed methodology; the possibilities for ethnicity analyses as available from the LIS/LES datasets; and the theoretical framework used to draw substantive cross-national comparisons. Section two comprises a summary of the descriptive patterns observed for selected indicators of social stratification by ethnic/nationality groups for each country, and the presentation of the SOR orderings derived from them. In section three, the possibilities for using those SOR orderings in analytical human capital style models of social stratification are considered. Lastly in section four some of the more prominent conclusions are drawn together.
Periodic Arrays of M2-Branes
We consider periodic arrays of M2-branes in the ABJM model in the spirit of a
circle compactification to D2-branes in type IIA string theory. The result is a
curious formulation of three-dimensional maximally supersymmetric Yang-Mills
theory in terms of fermions, seven transverse scalars, a non-dynamical gauge
field and an additional scalar `dual gluon'. Upon further T-duality on a
transverse torus we obtain a non-manifest-Lorentz-invariant description of
five-dimensional maximally supersymmetric Yang-Mills. Here the additional
scalar field can be thought of as the components of a two-form along the torus.
This action can be viewed as an M-theory description of M5-branes on .Comment: 20 pages, 1 figure, v3: typos corrected, published versio
Influence of shear reinforcement corrosion on the performance of under-reinforced concrete beams
The in-service performance of reinforced concrete beams can be severely affected through cor-rosion of the steel reinforcement when it becomes subjected to harsh corrosive environments containing chlo-rides and carbon dioxide. In such instances, corrosion is likely to occur in the steel reinforcement, with the expansive nature of the corrosion products likely to induce cracking and spalling of the concrete. A loss of structural integrity (stiffness) will occur and this can severely influence the serviceability of the member. The purpose of this paper is to investigate the relationship between degree of corrosion and loss of stiffness in corrosion damaged under-reinforced concrete beams. Beams (100mm x 150mm cross section) were subjected to accelerated corrosion in the laboratory and subsequently tested in flexure to failure. The paper reports on the results of these tests and relates the degree of corrosion in the main steel to the percentage loss in stiffness in the concrete beams
Accuracy assessment of Tri-plane B-mode ultrasound for non-invasive 3D kinematic analysis of knee joints
BACKGROUND Currently the clinical standard for measuring the motion of the bones in knee joints with sufficient precision involves implanting tantalum beads into the bones. These beads appear as high intensity features in radiographs and can be used for precise kinematic measurements. This procedure imposes a strong coupling between accuracy and invasiveness. In this paper, a tri-plane B-mode ultrasound (US) based non-invasive approach is proposed for use in kinematic analysis of knee joints in 3D space. METHODS The 3D analysis is performed using image processing procedures on the 2D US slices. The novelty of the proposed procedure and its applicability to the unconstrained 3D kinematic analysis of knee joints is outlined. An error analysis for establishing the method's feasibility is included for different artificial compositions of a knee joint phantom. Some in-vivo and in-vitro scans are presented to demonstrate that US scans reveal enough anatomical details, which further supports the experimental setup used using knee bone phantoms. RESULTS The error between the displacements measured by the registration of the US image slices and the true displacements of the respective slices measured using the precision mechanical stages on the experimental apparatus is evaluated for translation and rotation in two simulated environments. The mean and standard deviation of errors are shown in tabular form. This method provides an average measurement precision of less than 0.1 mm and 0.1 degrees, respectively. CONCLUSION In this paper, we have presented a novel non-invasive approach to measuring the motion of the bones in a knee using tri-plane B-mode ultrasound and image registration. In our study, the image registration method determines the position of bony landmarks relative to a B-mode ultrasound sensor array with sub-pixel accuracy. The advantages of our proposed system over previous techniques are that it is non-invasive, does not require the use of ionizing radiation and can be used conveniently if miniaturized.This work has been supported by School of Engineering & IT, UNSW Canberra, under Research Publication Fellowship
Review of \u3ci\u3eWill Rogers: A Political Life\u3c/i\u3e by Richard D. White Jr.
A child of the Southern Plains, Will Rogers became an iconic national figure in the 1920s and \u2730s. Renowned as a vaudevillian, a comedic movie star, a syndicated newspaper columnist, a radio commentator, and an author, Rogers\u27s significance as a political figure has largely been minimized or overlooked. Richard D. White Jr. demonstrates successfully that Rogers indeed was an influential political commentator whose support on behalf of various issues was sought and coveted by presidents from Woodrow Wilson to Franklin Roosevelt
Finite Element Modeling and Cellular Studies on Controlled Pores with Sub-Surface Continuity for Biomedical Applications
This work investigated a novel process for improving the reliability of load-bearing joint prosthetics, in which electrical discharge machining (EDM) is used to create pores with sub-surface continuity on a conventionally-fabricated prosthetic material. The first part of this investigation utilized in vitro studies to verify the biocompatibility of deep, high-aspect-ratio EDM-produced pores. Mesenchymal stem cells were seeded onto Grade 4 titanium samples with EDM-created pores, and osteodifferentiation and mineralization were induced and assessed. It was found that such pores allowed for cell proliferation and mineralization indicating good biocompatibility. The second part of this work utilized three dimensional finite element modeling (FEM) to characterize simulated porous implant interfaces under stress. Interlocking strengths of selected structures were verified, interface separation under applied stress was measured for these structures with implications for wear particle intrusion in the interfaces, and stress shielding analysis was performed on simulated implants containing intersecting and non-intersecting pores.
This work was supported in part by the National Science Foundation under Grant Number CMMI-0733522
Ethnicity and the comparative analysis of contemporary survey data
Der Verfasser macht auf drei signifikante Probleme bei der Analyse von EthnizitĂ€t im Rahmen internationaler Querschnittstudien aufmerksam: (1) Die Analyse von EthnizitĂ€t ist bisher im Quer- und LĂ€ngsschnitt nicht konsistent. (2) Harmonisierte Querschnittstudien leiden unter einem Mangel an Information in Bezug auf EthnizitĂ€t. (3) Harmonisierte Kategorisierungen spiegeln die RealitĂ€t des "ethnischen Mosaiks" weder quantitativ noch qualitativ adĂ€quat wider. Der Verfasser diskutiert zwei Lösungsmöglichkeiten fĂŒr diese Problematik. Ein "relativistischer" Ansatz zur Harmonisierung ethnischer Daten erfordert die Abbildung von Kategorisierungen auf einer Dimension ethnischer Ungleichheit und die Zuordnung quantitativer Werte, die ihre relative Position beschreiben. Ein "absolutistischer" Ansatz der Harmonisierung stellt sicher, dass fĂŒr alle LĂ€ndern die selben Konzepte zur Differenzierung von Kategorien eingesetzt werden. (ICE
Effect of Graphene Oxide Nanosheets on Physical Properties of Ultra-High-Performance Concrete with High Volume Supplementary Cementitious Materials
Nanomaterials have been increasingly employed for improving the mechanical properties and durability of ultra-high-performance concrete (UHPC) with high volume supplementary cementitious materials (SCMs). Recently, graphene oxide (GO) nanosheets have appeared as one of the most promising nanomaterials for enhancing the properties of cementitious composites. To date, a majority of studies have concentrated on cement pastes and mortars with fewer investigations on normal concrete, ultra-high strength concrete, and ultra-high-performance cement-based composites with a high volume of cement content. The studies of UHPC with high volume SCMs have not yet been widely investigated. This paper presents an experimental investigation into the mini slump flow and physical properties of such a UHPC containing GO nanosheets at additions from 0.00 to 0.05% by weight of cement and a waterâcement ratio of 0.16. The study demonstrates that the mini slump flow gradually decreases with increasing GO nanosheet content. The results also confirm that the optimal content of GO nanosheets under standard curing and under steam curing is 0.02% and 0.04%, respectively, and the corresponding compressive and flexural strengths are significantly improved, establishing a fundamental step toward developing a cost-effective and environmentally friendly UHPC for more sustainable infrastructure
Petrology of the Precambrian Rocks of Part of the Monte Largo Area, NM
Approximately 7 to 8 square miles of Precambrian rocks are exposed in the vicinity of the Monte Largo Hills in north-central New Mexico. The Precambrian rocks are bounded mainly by Pennsylvanian sedimentary rocks in both fault and noncomformable contact.
The area is made up largely of quartz-feldspar gneiss, hornblende gneiss, and quartzite. Quartz-feldspar gneiss is the most abundant rock type. Mica schist and sillimanite hornfels occur in minor amounts. Other Precambrian rocks include medium-grained granite, splite and pegmatite dikes, and quartz veins. A minor amount of migmatite is present as a result of the intimate association of quartz-feldspar gneiss and granite.
The metamorphic rocks are believed to have been derived largely from sedimentary rocks. The quartz-feldspar gneiss probably represents and feldspathic sandstone or subgraywacke; the hornblende gneiss, a graywacke; the quartzite, a rather pure quartz sandstone.
The Precambrian rocks have been subjected to three types of metamorphism: regional, thermal, and retrograde, in that order. The mineral assemblage hornblende-andesine-quartz in the hornblende gneiss indicates that regional metamorphism is of the almandite-amphibolite facies. Randomly oriented sillimanite in pelitic hornfels is indicative of either the hornblende-hornfels facies or the pyroxene-hornfels facies of thermal metamorphism. Retrograde alteration of biotite to muscovite, mangetite, and chlorite is indicative of the greenschist facies of metamorphism. Sericitization of plagioclase and sillimanite is widespread. There is some evidence that retrograde metamorphism was accompanied by introduction of potassium resulting in the formation of muscovite. The three types of metamorphism are believed to represent one period of metamorphism.
It is possible that granitization by the introduction of potassium to form microline has contributed to the formation of the quartz-feldspar gneiss.
Alkalic and related rocks younger than the plutonic rocks include a melteigite sill, carbonatite, and a breccia of explosive origin. The melteigite and carbonatite are similar to rocks associated with the alkalic stock at Iron Hill, Colorado.
The average strike of the foliation of the metamorphic rocks is northeast and the average dip is about 700 to the southwest
Preliminary Investigation into Modeling The Damage to Carbon Fibre Composites Due to the Thermo-electric Effects of a Lightning Strikes
The impact of a lightning strike causes a short high electrical current burst through Carbon Fibre Composites (CFC). Due to the electrical properties of CFC the large current leads to a rapid heating of the surrounding impact area which degrades and damages the CFC. It is therefore necessary to study in detail the thermal response and possible degradation processes caused to CFC. The degradation takes place in two ways, firstly via direct mechanical fracture due to the thermal expansion of the CFC and secondly via thermo-chemical processes (phase change and pyrolysis) at high temperatures. The main objective of this work is to construct a numerical model of the major physical processes involved, and to understand the correlation between the damage mechanisms and the damage witnessed in modern CFC. For this work we are only considering the thermo-chemical degradation of CFC. Bespoke numerical models have been constructed to predict the extent of the damage caused by the two thermo-chemical processes separately (e.g. a model for phase change and a model for pyrolysis). The numerical model predictions have then been verified experimental by decoupling of the damage mechanisms, e.g. the real Joule heating from a lightning strike is replaced by a high power laser beam acting on composite surface. This was done to simplify the physical processes which occur when a sample is damaged. The experimentally damaged samples were then investigated using X-ray tomography to determine the physical extent of the damage. The experimental results are then compared with the numerical predictions by considering the physical extent of the polymer removal. The extent of polymer removal predicted by the numerical model, solving for pyrolysis, gave a reasonable agreement with the damage seen in the experimental sample. Furthermore the numerical model predicts that the damage caused by polymer phase change has a minimal contribution to the overall extent of the damage
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