Single-dot Spectroscopy of GaAs Quantum Dots Fabricated by Filling of Self-assembled Nanoholes

We study the optical emission of single GaAs quantum dots (QDs). The QDs are fabricated by filling of nanoholes in AlGaAs and AlAs which are generated in a self-assembled fashion by local droplet etching with Al droplets. Using suitable process parameters, we create either uniform QDs in partially filled deep holes or QDs with very broad size distribution in completely filled shallow holes. Micro photoluminescence measurements of single QDs of both types establish sharp excitonic peaks. We measure a fine-structure splitting in the range of 22–40μeV and no dependence on QD size. Furthermore, we find a decrease in exciton–biexciton splitting with increasing QD size

Self-supporting End Effectors: Towards Low Powered Robots for High Power Tasks

AbstractNew tasks for industrial robots often require high stiffness or entail high reaction forces, which are currently provided by the robot structure itself. This leads to heavy and expensive robot structures: designed for the main task, but oversized for positioning and movement tasks.We propose a new approach to resolve these contradicting requirements: supporting the end effector directly against the workpiece or its surroundings, thus diverting the reaction forces away from the robot structure. We demonstrate this approach in a joining application and present design methods for self-supporting robotic tools as well as potential industrial applications of this technique

Quantized Dispersion of Two-Dimensional Magnetoplasmons Detected by Photoconductivity Spectroscopy

We find that the long-wavelength magnetoplasmon, resistively detected by photoconductivity spectroscopy in high-mobility two-dimensional electron systems, deviates from its well-known semiclassical nature as uncovered in conventional absorption experiments. A clear filling-factor dependent plateau-type dispersion is observed that reveals a so far unknown relation between the magnetoplasmon and the quantum Hall effect.Comment: 5 pages, 3 figure

Male Dress Habits in Roman Period Palmyra

Palmyra, ancient Tadmor, was in the first three centuries CE a flourishing trade node in theRoman Empire. Situated as the last stop on the Silk Road, camel caravans were reloaded ontodonkey caravans, and then went on to the areas west of Palmyra. Although having been underHellenistic influence for centuries, the region displays little tangible evidence of exactly howsuch influence impacted the societies in the region. With Pompey’s conquest in the 60s BCE,the region came under firm Roman control, and local societies responded to this interaction.This contribution looks at the material evidence from Palmyra from the period between the1st century CE and the late 3rd century CE in order to gauge the way in which Palmyrenemen were represented in the Palmyrene art. Most evidence stems from the funerary sphere,since the public and religious statuary largely has disappeared over the centuries. This paperconsiders the ways in which local and foreign clothing traditions impacted Palmyrene societyand shaped the expression of male identities in this oasis city

Monumental Development in Glanum: Evidence for the Early Impact of Rome in Gallia Narbonensis

This article challenges the prevailing opinion that the inhabitants of Gallia Transalpina were largely unaffected by Roman hegemony in the late second and early first centuries . The monumental development of the site of Glanum in the late second century shows clearly that the local elite were reacting to, and interacting with, their Roman conquerors. This relationship is not immediately obvious because the style of the architecture dating to the second century is described as Hellenistic rather than Roman. However, I argue that this incongruity should not affect the perception of change in the area. Given the current emphasis in the scholarly literature on the participation of local elites in the process of culture change, what matters is not whether the monuments are ‘Hellenistic’ or ‘Roman’, but rather the motivation and timing of their production

Status and Stasis: Looking at Women in the Palmyrene Tomb

The abundance of female funerary portraits from Palmyra makes them a tempting source for assessing the roles of women in ancient Palmyrene society. These bust-length portraits created in the first several centuries CE provide a wealth of detail on dress, adornment, family, and, in some cases, domestic activities. Although it has long been acknowledged that the portraits are not faithful renditions of the actual features and appearance of the deceased, the variability of gesture, dress, attributes, among other characteristics, suggests that the Palmyrenes did have some choice in the way in which they, or their family members, were represented. The correlation between these portraits and any kind of reliable indication of women’s roles in society is unlikely, however, since representations of women in the funerary sphere in general are normative, presenting an ideal to be achieved or societal priorities. Interpretation of the portraiture is further complicated by the political situation in Palmyra at the time of its production. Palmyra came under the control of Rome at some point in the late first century BCE to the early first century CE, and the funerary portraits are clearly modelled on Roman funerary sculpture. It is therefore difficult to discern the reasons behind certain stylistic choices: if they represented bona fide local priorities or socially potent references to a Roman paradigm. In this chapter, I focus on the bust-length relief portraits in the Palmyrene tombs, and the ways in which women are distinguished from men. Rather than providing any insight into the actual activities or position of women, this analysis will focus on the way in which the female modes of representation changed during the first three centuries CE, and reflect on the societal norms or priorities that dictated these changes

Gesture and Identity in the Funerary Art of Palmyra

The funerary art from Palmyra, a city in the eastern Roman empire, offers us a glimpse into the creation of social identity in the aftermath of Roman conquest. The Palmyrene portraits are modeled on the Roman funerary relief but with interesting local variations. For example, the deceased in these portraits hold their hands in a number of different positions. An analysis of these gestures reveals that some highlight certain aspects of the individuals represented, such as gender, profession, and family connections. The emphasis on these characteristics shows the multifaceted ways in which they defined themselves, and moves us beyond interpretations of identity that focus on a dichotomy between local and Roman