Fracture Mechanics Analysis of the Dentine-Luting Cement Interface.

The objectives of this study were to determine the fracture toughness of adhesive interfaces between dentine and clinically relevant, thin layers of dental luting cements. Cements tested included a conventional glass-ionomer, F (Fuji I), a resin-modified glass-ionomer, FP (Fuji Plus) and a compomer cement, D (DyractCem). Ten miniature short-bar chevron notch specimens were manufactured for each cement, each comprising a 40 µm thick chevron of lute, between two 1.5 mm thick blocks of bovine dentine, encased in resin composite. The interfacial KIC results (MN/m3/2) were median (range): F; 0.152 (0.14-0.16), FP; 0.306 (0.27-0.37), D; 0.351 (0.31-0.37). Non-parametric statistical analysis showed that the fracture toughness of F was significantly lower (p

Welfare Effort and Poverty from the Monetary and Capabilities Approach: A Cross-Country Analysis in Latin American and the Caribbean (1990-2010)

There is abundant empirical evidence on the negative relationship between welfare effort and poverty. However, poverty indicators traditionally used have been representative of the monetary approach, excluding its multidimensional reality from the analysis. Using three regression techniques for the period 1990-2010 and controlling for demographic and cyclical factors, this paper examines the relationship between social spending per capita —as the indicator of welfare effort— and poverty in up to 21 countries of the region. The proportion of the population with an income below its national basic basket of goods and services (PM1) and the proportion of population with an income below 50% of the median income per capita (PM2) were the two poverty indicators considered from the monetarist approach to measure poverty. From the capability approach the proportion of the population with food inadequacy (PC1) and the proportion of the population without access to improved water sources or sanitation facilities (PC2) were used. The fi ndings confi rm that social spending is actually useful to explain changes in poverty (PM1, PC1 and PC2), as there is a high negative and signifi cant correlation between the variables before and after controlling for demographic and cyclical factors. In two regression techniques, social spending per capita did not show a negative relationship with the PM2. Countries with greater welfare effort for the period 1990-2010 were not necessarily those with the lowest level of poverty. Ultimately social spending per capita was more useful to explain changes in poverty from the capability approach.

Organizational and financial transparency in the website of the foundations: an empirical study for Spain

Transparency in nonprofit sector and foundations, as an element to enhance the confidence of stakeholders in the organization, is a fact shown by several studies in recent decades. Transparency can be considered in various fields and through different channels. In our study we focused on the analysis of the organizational and economic transparency of foundations, shown through the voluntary information on their Website. We review the theoretical previous studies published to put to the foundations within the framework of the social economy. This theoretical framework has focused on accountability that make foundations in relation to its social function and its management, especially since the most recent focus of information transparency across the Website.In this theoretical framework was made an index to quantify the voluntary information which is shown on its website. This index has been developed ad hoc for this study and applied to a group of large corporate foundations.With the application of these data are obtained two kind of results, to a descriptive level and to a inferential level.We analyzed the statistical correlation between economic transparency and organizational transparency offered in the Website through quantified variables by a multiple linear regression. This empirical analysis allows us to draw conclusions about the level of transparency offered by these organizations in relation to their organizational and financial information, as well as explain the relation between them.

Modelling the correlation between processing parameters and properties of maraging steels using artificial neural network

An artificial neural network (ANN) model is developed for the analysis and simulation of the correlation between the properties of maraging steels and composition, processing and working conditions. The input parameters of the model consist of alloy composition, processing parameters (including cold deformation degree, ageing temperature, and ageing time), and working temperature. The outputs of the ANN model include property parameters namely: ultimate tensile strength, yield strength, elongation, reduction in area, hardness, notched tensile strength, Charpy impact energy, fracture toughness, and martensitic transformation start temperature. Good performance of the ANN model is achieved. The model can be used to calculate properties of maraging steels as functions of alloy composition, processing parameters, and working condition. The combined influence of Co and Mo on the properties of maraging steels is simulated using the model. The results are in agreement with experimental data. Explanation of the calculated results from the metallurgical point of view is attempted. The model can be used as a guide for further alloy development.

The Impact of Disrespect on Prisoners’ Aggression: Outcomes of Experimentally Inducing Violence Supportive Cognitions

Self-report research suggests that much violence is triggered by perceived insults and disrespect. This may be particularly true in the context of a prison or another environment of acute deprivation, whereby individuals have little other recourse to means of reputation enhancement. This paper presents the findings of two studies conducted with prisoner volunteers inside a Category C (minimum security) prison in England. In the first study, the authors randomly assigned a sample of 89 prisoners to one of two conditions: the experimental group were asked to discuss times they have been disrespected by authority figures inside and outside the prison; the control group were asked more neutral questions. Both groups then completed several measures of cognitive beliefs, distortions, and hostile attribution biases. None of the measures differed across the two groups except the measure of excuse and justification acceptance. Controlling for other factors, the experimental group endorsed these rationalisations at a significantly higher rate than the control group. This finding suggests that raising the salience of disrespect - reminding prisoners of times they have been made to feel unworthy of consideration - may raise the risk that prisoners will engage in violence by providing prisoners with justifications or excuses for actions they might not otherwise endorse. These findings received some additional validation in the second study, a qualitative analysis of offender accounts of violence and aggression within the prison. Implications for reducing violence within prisons are discussed.

Understanding online customer repurchasing intention and the mediating role of trust - an empirical investigation in two developed countries

Although e-commerce adoption and customers initial purchasing behavior have been well studied in the literature, repeat purchase intention and its antecedents remain understudied. This study proposes a model to understand the extent to which trust mediates the effects of vendor-specific factors on customers intention to repurchase from an online vendor. The model was tested and validated in two different country settings. We found that trust fully mediates the relationships between perceived reputation, perceived capability of order fulfillment, and repurchasing intention, and partially mediates the relationship between perceived website quality and repurchasing intention in both countries. Moreover, multi-group analysis reveals no significant between-country differences of the model with regards to the antecedents and outcomes of trust, except the effect of reputation on trust. Academic and practical implications and future research are discussed. © 2009 Operational Research Society Ltd.

Nitride-strengthened reduced activation ferritic/martensitic steels

Two nitride-strengthened reduced activation ferritic/martensitic (RAFM) steels with different Mn contents were investigated. The experimental steels were designed based on the chemical composition of Eurofer 97 steel but the C content was reduced to an extremely low level. Microstructure observation and hardness tests showed that the steel with low Mn content (0.47 wt.%) could not obtain a full martensitic microstructure due to the inevitable δ-ferrite independent of cooling rate after soaking. This steel showed similar room temperature strength and higher strength at 600 °C, but lower impact toughness, compared with Eurofer 97 steel. Fractography of the Charpy impact specimen revealed that the low room temperature toughness should be related to the Ta-rich inclusions initiating the cleavage fracture. The larger amount of V-rich nitrides and more dissolved Cr in the matrix could be responsible for the strength being similar to Eurofer 97 steel. In the second steel developed from the first steel by increasing the Mn content from 0.47 wt.% to 3.73 wt.%, a microstructure of full martensite could be obtained.

Precipitation, microstructure and mechanical properties of low nickel maraging steel

A maraging steel with a composition of Fe–12·94Ni–1·61Al–1·01Mo–0·23Nb (wt-%) was investigated. Optical, scanning electron and transmission electron microscopy and X-ray diffraction analysis were employed to study the microstructure of the steel after different aging periods at temperatures of 450–600°C. Hardness and Charpy impact toughness of the steel were measured. The study of microstructure and mechanical properties showed that nanosized precipitates were formed homogeneously during the aging process, which resulted in high hardness. As the aging time is prolonged, precipitates grow and hardness increases. Fractography of the as forged steel has shown mixed ductile and brittle fracture and has indicated that the steel has good toughness. Relationships among heat treatment, microstructure and mechanical properties are discussed. Further experiments using tensile testing and impact testing for aged steel were carried out.

Repurchase intention in B2C e-commerce—A relationship quality perspective

Information systems professionals must pay attention to online customer retention. Drawing on the relationship marketing literature, we formulated and tested a model to explain B2C user repurchase intention from the perspective of relationship quality. The model was empirically tested through a survey conducted in Northern Ireland. Results showed that online relationship quality and perceived website usability positively impacted customer repurchase intention. Moreover, online relationship quality was positively influenced by perceived vendor expertise in order fulfillment, perceived vendor reputation, and perceived website usability, whereas distrust in vendor behavior negatively influenced online relationship quality. Implications of these findings are discussed. © 2011 Elsevier B.V. All rights reserved.

Geological fakes and frauds

Some geological fakes and frauds are carried out solely for financial gain (mining fraud), whereas others maybe have increasing aesthetic appeal (faked fossils) or academic advancement (fabricated data) as their motive. All types of geological fake or fraud can be ingenious and sophisticated, as demonstrated in this article. Fake gems, faked fossils and mining fraud are common examples where monetary profit is to blame: nonetheless these may impact both scientific theory and the reputation of geologists and Earth scientists. The substitution or fabrication of both physical and intellectual data also occurs for no direct financial gain, such as career advancement or establishment of belief (e.g. evolution vs. creationism). Knowledge of such fakes and frauds may assist in spotting undetected geological crimes: application of geoforensic techniques helps the scientific community to detect such activity, which ultimately undermines scientific integrity.

Vaughan Williams and contemporary music: composers' forum

Like many long-lived composers, Vaughan Williams suffered a decline in his reputation immediately following his death, as the emergence in the 1960s of a younger generation of composers rendered much of his work outmoded in the eyes of many critics. In recent years, however, the reception of Vaughan Williams's music among composers has improved markedly, a combination of the ebbing of the tide of high modernism and greater pluralism in contemporary music, and a growing awareness that Vaughan Williams was perhaps more modernist (or at least progressive) than had previously been thought. In interviews with four leading British composers (two of whom were part of the 1960s generation mentioned above), I investigate the nature and extent of Vaughan Williams's legacy to his successors, both musical and social. What emerges is a near consensus on Vaughan Williams's greatest works, but a diversity of views on his compositional techniques and on his place among his European contemporaries.

Microstructure and mechanical properties of low nickel maraging steel

Austenitization with lower temperature and intercritical annealing were introduced in the treatment of a maraging steel with a composition of Fe–12.94Ni–1.61Al–1.01Mo–0.23Nb (wt.%). Scanning electron microscopy was employed to study the microstructure after austenitization at 950 °C and intercritical annealing, followed by aging at 485 and 600 °C. X-ray diffraction (XRD) analysis was applied to evaluate the formation of retained or reverted austenite. Thermodynamic calculation was employed to calculate equilibrium phase mole fractions. Hardness and Charpy impact toughness of the steel were measured. Intercritical annealing treatments did not result in significant increase of hardness either before or after aging. The Charpy impact toughness of the alloy in aged condition was enhanced after austenitization at 950 °C. No austenite was observed in XRD. However, suspected reverted austenite was found after austenitization at 950 °C followed by aging at 600 °C for 4 h. Relationships among heat treatment, microstructure and mechanical properties are discussed.

Fracture surface, impact energy and hardness of Ni-free high-Mn steels

Two manganese steels were investigated: Fe-19.7%Mn (VM339A) and Fe-19.7%Mn stabilized with 0.056%C, 0.19%Ti and 0.083%Al (VM339B). The toughness of VM339A was higher than VM339B, but VM339B had higher hardness. Tempering does not affect the toughness of the alloys. SEM images of the fracture surface for both the alloys revealed ductile fractures. A further alloy with a lower manganese content, Fe-8.46%Mn-0.24%Nb-0.038%C, and thus even lower cost than the conventional 3.5Ni cryogenic steel, was tested for its impact toughness after heat treatment at 600°C, giving promising results.

Developing Empirically-Based Practice in Probation

This article examines the influence of research on social work practice, with special reference to probation, and argues that in order to maintain their well-earned reputation as providers of defensible alternatives to custody, probation officers need to attend more carefully to the findings of research and to review their practice accordingly. Further, it is argued that managers need to consider the content of practice as well as its structure, if they are to meet the challenges of the present decade. These discussions are placed in the context of an applied research project on one probation team's attempt to adopt a more structured and empirically-based approach to the setting up of a new groupwork programme.

Flexural performance of fibre reinforced concrete made with steel and synthetic fibres

The ductility of concrete made with commercially available steel and synthetic fibres has been investigated. Flexural stress–deflection relationships have been used to determine: flexural strength, flexural toughness, equivalent flexural strength, and equivalent flexural strength ratio. The flexural toughness of concrete was found to increase considerably when steel and synthetic fibres were used. However, equal dosages of different fibres did not result in specimens with the same flexural toughness. Flexural toughness differences of almost 35 J existed even at the same fibre dosage. This also resulted in considerable differences in the minimum required ground supported slab thickness.