739 research outputs found
Optofluidic random laser
An active disordered medium able to lase is called a random laser (RL). We
demonstrate random lasing due to inherent disorder in a dye circulated
structured microfluidic channel. We consistently observe RL modes which are
varied by changing the pumping conditions. Potential applications for on-chip
sources and sensors are discussed.Comment: 3 pages, 4 figure
Models with short and long-range interactions: phase diagram and reentrant phase
We study the phase diagram of two different Hamiltonians with competiting
local, nearest-neighbour, and mean-field couplings. The first example
corresponds to the HMF Hamiltonian with an additional short-range interaction.
The second example is a reduced Hamiltonian for dipolar layered spin
structures, with a new feature with respect to the first example, the presence
of anisotropies. The two examples are solved in both the canonical and the
microcanonical ensemble using a combination of the min-max method with the
transfer operator method. The phase diagrams present typical features of
systems with long-range interactions: ensemble inequivalence, negative specific
heat and temperature jumps. Moreover, in a given range of parameters, we report
the signature of phase reentrance. This can also be interpreted as the presence
of azeotropy with the creation of two first order phase transitions with
ensemble inequivalence, as one parameter is varied continuously
The Janus head of Bachelardâs phenomenotechnique: from purification to proliferation and back
The work of Gaston Bachelard is known for two crucial concepts, that of the epistemological rupture and that of phenomenotechnique. A crucial question is, however, how these two concepts relate to one another. Are they in fact essentially connected or must they be seen as two separate elements of Bachelard's thinking? This paper aims to analyse the relation between these two Bachelardian moments and the significance of the concept of phenomenotechnique for today. This will be done by examining certain historical uses of the concepts of Bachelard have been used from the 1960s on. From this historical perspective, one gets the impression that these two concepts are relatively independent from each other. The Althusserian school has exclusively focused on the concept of 'epistemological break', while scholars from Science & Technology Studies (STS), such as Bruno Latour, seem to have only taken up the concept of phenomenotechnique. It in fact leads to two different models of how to think about science, namely the model of purification and the model of proliferation. The former starts from the idea that sciences are rational to the extent that they are purified and free from (epistemological) obstacles. Scientific objectivity, within this later model, is not achieved by eradicating all intermediaries, obstacles and distortions, but rather exactly by introducing as many relevant technical mediators as possible. Finally, such a strong distinction will be criticized and the argument will be made that both in Bachelard's and Latour's thought both concepts are combined. This leads to a janus-headed view on science, where both the element of purification (the epistemological break) and the element of proliferation (phenomenotechnique) are combine
Bodily relations and reciprocity in the art of Sonia Khurana
This article explores the significance of the âsomaticâ and âontological turnâ in locating the radical politics articulated in the contemporary performance, installation, video and digital art practices of New Delhi-based artist, Sonia Khurana (b. 1968). Since the late 1990s Khurana has fashioned a range of artworks that require new sorts of reciprocal and embodied relations with their viewers. While this line of art practice suggests the need for a primarily philosophical mode of inquiry into an art of the body, such affective relations need to be historicised also in relation to a discursive field of âdifferenceâ and public expectations about the artistâs ethnic, gendered and national identity. Thus, this intimate, visceral and emotional field of inter- and intra-action is a novel contribution to recent transdisciplinary perspectives on the gendered, social and sentient body, that in turn prompts a wider debate on the ethics of cultural commentary and art historiography
Psychopolitics: Peter Sedgwickâs legacy for mental health movements
This paper re-considers the relevance of Peter Sedgwick's Psychopolitics (1982) for a politics of mental health. Psychopolitics offered an indictment of âanti-psychiatryâ the failure of which, Sedgwick argued, lay in its deconstruction of the category of âmental illnessâ, a gesture that resulted in a politics of nihilism. âThe radical who is only a radical nihilistâ, Sedgwick observed, âis for all practical purposes the most adamant of conservativesâ. Sedgwick argued, rather, that the concept of âmental illnessâ could be a truly critical concept if it was deployed âto make demands upon the health service facilities of the society in which we liveâ. The paper contextualizes Psychopolitics within the âcrisis tendenciesâ of its time, surveying the shifting welfare landscape of the subsequent 25 years alongside Sedgwick's continuing relevance. It considers the dilemma that the discourse of âmental illnessâ â Sedgwick's critical concept â has fallen out of favour with radical mental health movements yet remains paradigmatic within psychiatry itself. Finally, the paper endorses a contemporary perspective that, while necessarily updating Psychopolitics, remains nonetheless âSedgwickianâ
Colonization, disability, and the intranet: the ethnic cleansing of space?
The article analyzes teacherâs emplacement of the image of disability within schoolâs intranet sites in England. The image unearthed within such sites was problematic as it did not display a positive or realistic image of disability or disabled people. Within the article historical archaeology and colonialism are employed as theoretic framework to interpret this artifact of disability. The article also provides an ethnographic subscript to the creation of a space of possibilities and how this became striated by missionary teachers who colonized this brave new intranet world. Deciphering of the organization and representation of the disabled indigene, through this theoretical framework, unearthed a cartography inscribed by the scalpel of old world geometry
A fresh look at instrumentation - an introduction
The theme of "instrumentation between science, state and industry" does not square well with the venerable discourse which opposes "science" and "technology" in social studies of science. In this discourse, "technology" stands for the contrary of "science"; it represents the practical uses of science in society at large and is understood as separate from the somehow autonomous sphere of "science" (Layton 1971a). This vocabulary, widespread as it may be, is not very useful for our purposes, and, for that matter, for any inquiry into the role of instruments. Technology, in the sense of technical instruments and the knowledge systems that go with them, pervades all societal systems. There are technologies of science, of industry, of state, and so forth, and it would be ill-advised to assume that, in the end, they all flow out of "science." But even if the crude opposition of science and technology has little analytic value, the dual problem remains: how to effectively conceive the dynamic relationship between scientific spheres and other societal spheres, and how to conceive the role that technological matters play in this relationship
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