Search results

Internal gearings are commonly used in transmissions due to their advantages like high-power density. To ensure high efficiency, load-carrying capacity and good noise behavior, a profound knowledge of the local gear mesh is essential. The tooth contact of internal gears relates to a convex and concave surface that form a conformal contact. This is in contrast to external gears, where two convex surfaces form a contraformal contact. This paper aims at a better understanding of conformal contacts under elastohydrodynamic lubrication (EHL) to improve the design of internal gearings.

An existing numerical EHL model is used for studying the characteristic properties of a hard conformal EHL line contact. A hard contraformal EHL line contact is studied as reference. Non-Newtonian fluid behavior and thermal effects are considered. By taking into account the local contact conformity and kinematics, the effects and relevance of the curvature of the lubricant gap and micro-slip are analyzed. In a parameter study, scale effects of the contact radii on film thickness, temperature rise and friction are examined.

The curvature of the lubricant gap and effects of micro-slip are small in hard conformal EHL line contacts. For high micro-slip, it can be neglected. Hence, the modeling of conformal contacts using an equivalent geometry of the contact problem is reasonable. The parameter study shows beneficial tribological aspects of the conformal contact compared to the contraformal contact. Higher film thickness and lower fluid coefficient of friction are observed for conformal contacts, which can be attributed to lower pressures for the case of the same external normal force, or to a higher contact temperature rise for the case of equivalent contact pressure.

Despite its widespread existence, the local geometry and kinematics in hard conformal EHL line contacts like in internal gearings have been rarely studied. The findings help for a better understanding of local contact characteristics and its relevance. The quantified scale effects help to improve the efficiency and load-carrying capacity of machine elements with hard conformal EHL contacts, like internal gearings.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2022-0366/

This case study chapter reviews the evidence related to TransMilenio (TM) and its ability to promote walking among Bogotá’s citizens. A historical perspective of the Bus Rapid Transit system in Latin America and Bogotá is provided as well as some of the social, environmental and cultural implications. Through a literature review, studies that specifically assessed the role of TM in the promotion of walking and active transportation were identified. In addition, experts in the field were contacted to receive additional papers or reports from the grey literature that could have been missed through the peer-reviewed literature search. In December 2000, Bogotá implemented TM. The system has been successful in reducing traffic congestion, environmental pollution and travel times, as well as improving mobility in the city. Although not initially a goal of TM, some evidence suggests that the system has also served to promote walkability in the city. TM users are more likely to meet recommendations for daily moderate-to-vigorous physical activity and for walking for transportation, reaching an average of 22 minutes per day. Despite its many benefits, TM has some shortcomings that need to be recognised and addressed. In 2014, the daily number of TM users (2.2 million) surpassed the number of users of the traditional public transportation system, but there has still been a migration of users to private means of transportation such as motorcycles and automobiles.

Anti-racism has been practiced in various ways, with varying degrees of effectiveness. This chapter engages with the body of scholarship that focuses on approaches aimed at promoting anti-racist actions, policies and social change. It discusses some of the main anti-racism strategies that have been deployed across different countries and examines anti-racism practices in interpersonal, intergroup and community settings. These approaches encompass civil rights campaigns, legislative and policy interventions, affirmative action, diversity and inclusion training, prejudice reduction, intergroup contact, organisational development and holistic anti-racism approaches. Some anti-racism practices and policies, such as awareness campaigns, social marketing and diversity training, also extend to digital platforms, with social media and multimedia networks deployed to broaden the reach and impact of anti-racist endeavours. This chapter specifically engages with local anti-racism movements and draws principles for broader implementation of anti-racism policy and practice. It concludes with a brief discussion of the effectiveness of contemporary anti-racism approaches.

This chapter provides an introduction to the world of family companies and family constitutions from a legal perspective. It first studies the legal types of business organizations that family firms have chosen across time and jurisdictions. It then illustrates how early predecessors of family constitutions evolved in the late Middle Ages and what modern family constitutions look like in different countries today. Further considerations are devoted to the governance framework of family firms. The chapter concludes by exploring the potential legal effects of family constitutions under German company and contract law.

Part II and last MECHETTI. Vienna FOUNDED in 1795 by Carlo Mechetti as a dealer; since 1807 in partnership with his nephew, Pietro; the publishing firm styled Carlo Mechetti & Neffe in 1809; after Carlo's death in 1811, Pietro became sole owner; he was succeeded in 1850 by his widow, Therese; c. 1855 the firm was taken over by A. Diabelli & co. (cp. Peter Cappi).

This chapter starts with a short discussion of social work and how it interlinks educational issues with forms of support to enable people to cope with difficult situations. An example shall illustrate that a global perspective on questions of governance in social work has to consider the historical, economic, and political context in which it takes place. It will then be argued that “governance building” might be a fundamental necessity in strengthening the empowerment of people, and this means accepting the ambivalence of support and control. In this context, some distinguished authors will be identified who considered social movements as motors of governance bringing in normative aspects, which cannot be reduced to functional theory. Finally, the chapter concludes by reflecting on the role of research in defining support programs in welfare states.

A Recent work in information studies re-engages with theories of subject enunciation first developed in the work of twentieth century structuralist and post-structuralist critics. To date this work has not been extended to the analysis of data visualizations. The purpose of this paper is to assert that information visualizations embody specific dynamics of positionality for which linguist Emile Benveniste’s formulation of a speaking and spoken subject provides a critical analytic framework. In particular, enunciative theory can be used to explicitly address the mechanisms of power formation in information graphics “spreadsheets, charts and interfaces” that are frequently seen as mere presentations of quantitative or statistical information. This approach is based on attention to the performative aspects of graphic expression and the ways familiar features such as frontality framing and scale can be read critically.

A theoretical argument that applies literature in enunciation as developed in linguistics, film theory, and psychoanalysis to information visualizations. The paper makes specific analyses of the graphical features of spreadsheets, common charts and graphs, and interfaces to show how they create speaking and spoken subject positions.

The theory of enunciation is useful in understanding the ways information representations, particularly visualizations of data, work to produce power relations.

The topic may seem to draw on theoretical positions that are associated with structural and post-structural theory popular three decades ago, but since the study of enunciation was never applied to information visualizations, the work feels timely. Recent work in information studies has re-engaged with these theoretical issues, but not applied them to charts, graphs, and other visual forms. Information visualizations are so prevalent that any critical insight into their operations feels timely, even urgent.

The concept of information as enunciation in recent work in information studies has not been applied to visualizations. Analysis of the production of subject positions as commonly understood in other fields (linguistics, textual studies, film studies, visual studies, and psychoanalysis across a broad range of cultural studies fields) can be usefully applied to information graphics.

This paper discusses how corruption, in its various manifestations, has had — and continues to have — a very serious impact on the economic and political stability of the Asia‐Pacific region.

The purpose of this paper is to use an environmental criminology and situational crime prevention (SCP) framework to study global assassinations carried out by terrorists. The authors set forth a series of hypotheses to explain successful and unsuccessful assassination incidents.

The authors use assassination data from the Global Terrorism Database from 1970 to 2014 to estimate a series binary logistic regression models.

Results indicate that various situational factors contribute to successful assassinations, such as target types, weapon types, total fatalities, and injuries.

These findings suggest that environmental criminology and SCP are valuable in developing prevention measures that thwart and disrupt attempted assassinations by terrorists.

Criminology has yet to apply environmental criminology and SCP to assassinations, a tactic often used by terrorists. This paper thus extends the existing assassination, terrorism, and criminology literature by applying this framework to assassinations performed by terrorists.