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Like any established and mature body of scholarship, social movements research has changed, evolved, and grown over its decades. Now a robust and vibrant field in its own right, it has seen interpretive paradigms and theoretical frameworks come and go, and in some cases come again. A variety of frameworks and approaches have been used, emphasizing collective behavior, mobilizing structures, resource mobilization, cultural politics, social psychology, identities, cognition, framing, discourses, narratives, and emotions.

The news of recent mobilizations in Arab, European, and North-American countries quickly spread across the globe. Well before written reports analyzing the unfolding mobilizations, images of protests circulated widely through television channels, print newspapers, internet websites, and social media platforms. Pictures and videos of squares full of people protesting against their governments became the symbols of a new wave of contention that quickly spread from Tunisia to many other countries. Pictures and videos showing the gathering of people in Tahrir square (Egypt), Puerta del Sol (Spain), and Zuccotti Park (United States) quickly became vivid tools of “countervisuality” (Mirzoeff, 2011) that opposed the roaring grassroots political participation of hundreds of thousands people to the silent decisions taken in government and corporation buildings by small groups of politicians and managers. The presence, and relevance, of images in mobilizations of social movements is no novelty. Encounters with social movements have always been intrinsically tied to the visual sense. Activists articulate visual messages, their activities are represented in photos and video sequences, and they are ultimately rendered visible, or invisible, in the public sphere. Social movements produce and evoke images, either as a result of a planned, explicit, and strategic effort, or accidentally, in an unintended or undesired manner. At the same time, social movements are perceived by external actors and dispersed audiences via images which are produced both by themselves and others.

This chapter provides an analysis of images produced and employed in protests against surveillance in Germany in 2008 and 2009. For this purpose, a method of visual analysis is developed that draws mainly on semiotics and art history. Following this method, the contribution examines a selection of images (pictures and graphic design) from the anti-surveillance protests in three steps: description of components, detection of conventional signs, and contextual analysis. Furthermore, the analysis compares the images of the two major currents of the protest (liberal and radical left) in order to elucidate the context in which images are created and used. The analysis shows that images do not merely illustrate existing political messages but contribute to movements’ systems of meaning creation and transportation. The two currents in the protests communicate their point of view through the images both strategically and expressively. The images play a crucial role in formulating groups’ different strategies as well as worldviews and identities. In addition, the analysis shows that the meaning of images is contested and contextual. Images are produced and received in specific national as well as issue contexts. Future research should address the issue of context and reception in greater depth in order to further explore the effects of visual language on mobilization. Overall, the contribution demonstrates that systematic visual analysis allows our understanding of social movements’ aims, strategy, and collective identity to be deepened. In addition, visual analysis may provide activists with a tool to critically assess their visual communication.

This paper aims to compare the conditions of in-service oils from diesel and gasoline engines, with focus on nitration.

Oil conditions of seven engine oil samples from five diesel-fueled vehicles and nine oil samples from eight gasoline-fueled vehicles with total mileage ranging from 13,600 to 30,000 km were determined via Fourier-transform infrared spectroscopy as well as neutralization number (NN) and total base number titration.

Chemical deterioration was characterized by significant differences in oxidation, nitration, NN increase and residual aminic antioxidant contents.

Submitted in connection with the Special Issue, “Young Tribologists – Insights into the work of the new generation”.

Uncovering differences in the oil degradation of oils from gasoline and diesel engines enables improved condition-based maintenance strategies and the prediction of oil condition dependent tribological performance.

The chapter starts with some reflections on the different ways in which scholars (implicitly, if not explicitly) perform visual analysis in their own work. For social movement scholars, in fact, the choice of logos for research centers, the selection of pictures for presentation slides, or the designing of covers for books all signal not only esthetic tastes but also specific conceptions of their object of studies. Moving from these experiences to some empirical analysis of the images collected in the place where young activist Carlo Giuliani was killed during a police charge at the counter summit against the G8 in Genoa in 2001, the chapter suggests some line of reflections on the production and use of images in social movements.

Tina Askanius is a lecturer and researcher in the Department of Communication and Media at Lund University, Sweden. Her research concerns social movement media practices with a particular focus on contemporary forms of video activism in online environments. Her recent work within this area has been published in international journals such as Journal of E-politics, Journal of Electronic Governance, and Interface: a journal for and about social movements.

The purpose of this paper is to study the friction and wear behavior of germanium (Ge) thin films deposited by low-pressure chemical vapor deposition method on a chromium (Cr)-nickel (Ni) stainless steel substrate after being exposed to relatively mild sliding conditions (low loads and sliding distances).

Wear and friction experiments were conducted with a 100Cr6 steel ball sliding against flat Ge thin-film-coated stainless steel sheets (ball-on-flat microtribometer, no lubricant, normal loads of 50-100 mN, initial Hertzian contact pressures of 385-485 MPa, total sliding distance up to 200 mm and room temperature).

Scanning electron microscopy results revealed that prepared Ge thin films consisted of two different morphologies: curved nanowires and cone-shaped nano-/microdroplets. Regarding friction and wear characteristics of the investigated samples, the substrates coated with Ge thin films did not affect the coefficient of friction significantly by load. The wear of the base material (Cr-Ni stainless steel) was not observed under the mentioned experimental conditions (see the “Design/methodology/approach” section); however, with increased sliding distance and/or applied load, a rupture of the Ge film and an exposure of the stainless steel substrate to the 100Cr6 ball can be expected. Furthermore, the observations suggest that the smearing of Ge nano- and microstructures, plastically deformed during tribotesting, over the surface exposed to the sliding contact is the dominant tribological process.

For the first time, the tribological interaction between Ge thin film and steel surface was investigated under dry sliding conditions using a ball-on-flat microtribometer, and the obtained results provide a useful base for the further research on tribology of Ge-based thin films.