63 research outputs found
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Low-energy degassing mechanisms for a fluid-based radioxenon detection system
A method to concentrate heavy noble gases from the atmosphere using certain organic fluids is being developed. To use this technique in a system to monitor the atmosphere for important noble gas fission products (Xe-131, Xe-131m, Xe-133, Xe-133m, and Xe-135) generated by nuclear testing, the radionuclides captured in the fluid must either be detected in the fluid or degassed. This study presents experimental results for a number of possible degassing methods, including heating bubbling with a purge gas, ultrasonic agitation, vacuum, and combinations thereof. Methods were evaluated for energy and time requirements and dilution of the degas product. Initial experiments indicate that in addition to overcoming the standard desorption process dictated by partial pressures per Henry`s Law, a capture mechanism must also be overcome to degas. Some type of agitation, thermal or mechanical, can be used to release weakly trapped gas atoms from the fluid, while diffusional mass transfer can be enhanced through entrainment with a purge gas or use of a vacuum. Ultrasonic agitation of a thin film in a strong vacuum has been shown to be the most effective method of those tested. Implementation of an efficient degas system, along with an absorption system and radioxenon detector could result in an ultrasensitive fluid-based radioxenon measurement system that is more portable, less expensive, and simpler than charcoal-based systems which use cryogenic techniques
Stasis and Change: Russia and the Emergence of an Anti-Hegemonic World Order
This chapter argues that after a quarter century of stasis, the pattern of world order is changing and the inter-cold war period of the cold peace is giving way not to a thaw, but to the re-entrenchment of bipolar confrontation between the expansive liberal international order and the resistance of a group of states including Russia. Like the First Cold War, the second is also about the conflicting views of world order as the U.S.-led liberal international order is challenged by the emergence of a putative anti-hegemonic alignment between Russia, China and their allies in the emerging alternative architecture of world affairs – especially the Shanghai Cooperation Organization (SCO) and BRICS (Brazil, Russia, India, China, South Africa). The clash between Russia and the West, in this sense, is only an early version – and ultimately perhaps not the most significant – of the challenges against the long-term stasis in international affairs. Although the sinews of a post-Western world are emerging, it remains to be seen whether bodies like SCO and BRICS will be able to sustain the multilateralism of the last seven decades in the absence of the hegemon that had provided the security and support for such multilaterialism to thrive
Negotiating the modern cross-class ‘model home’:domestic experiences in Basil Spence’s Claremont Court
This article investigates the spatial articulation of architecture and home through the exploration of current domestic experiences in Basil Spence’s Claremont Court housing scheme (1959-1962), Edinburgh. How architecture and home are both idealized and lived is the backdrop for a discussion that draws on the concept of “model home,” or physical representation of a domestic ideal. The article reads Claremont Court as an architectural prototype of the modern domestic ideal, before exploring its reception by five of its households through the use of visual methods and semistructured interviews. Receiving the model home involves negotiating between ideal and lived homes. Building on this idea, the article contributes with a focus on the spatiality of such reception, showing how it is modulated according to the architectural affordances that the “model home” represents. The article expands on scholarship on architecture and home with empirical evidence that argues the reciprocal spatiality of home
Normative resistance to responsibility to protect in times of emerging multipolarity: the cases of Brazil and Russia
This article assesses the normative resistance to Responsibility to Protect adopted by Brazil and Russia against the backdrop of their international identities and self-assigned roles in a changing global order. Drawing upon the framework of Bloomsfield's norm dynamics role spectrum, it argues that while the ambiguous Russian role regarding this principle represents an example of 'norm antipreneurship', particularities of Brazil's resistance are better grasped by a new category left unaccounted for by this model, which this study portrays as 'contesting entrepreneur'.- (undefined
One Europe or None? Monism, Involution and Relations with Russia
The crisis in relations between Russia and the European Union (EU) is part of the broader breakdown of the post-Cold War security order. This commentary focuses on structural interpretation and identifies four interlinked processes shaping the crisis: tension between the logic of the enlargement and transformation; a dynamic of involution and resistance; the problem of monism, whereby the expanding self is unable adequately to engage with the un-integrated other; and the recent emergence of ‘other Europes’ that may potentially overcome involution. The erosion of the Atlantic system provides an opportunity for delayed institutional and ideational innovation
Global transcriptome analysis of genetically identified neurons in the adult cortex
The enormous cellular complexity of the brain is a major obstacle for gene expression profiling of neurological disease models, because physiologically relevant changes of transcription in a specific neuronal subset are likely to be lost in the presence of other neurons and glia. We solved this problem in transgenic mice by labeling genetically defined cells with a nuclear variant of GFP. When combined with laser-directed microdissection, intact RNA from unfixed, freeze-dried sections can be isolated, which is a prerequisite for high-quality global transcriptome analysis. Here, we compared gene expression profiles between pyramidal motor neurons and pyramidal somatosensory neurons captured from layer V of the adult neocortex. One striking feature of motor neurons is the elevated expression of ribosomal genes and genes involved in ATP synthesis. This suggests a molecular adaptation of the upper motor neurons to longer axonal projections and higher electrical activity. These molecular signatures were not detected when cortical layers and microareas were analyzed in toto. Additionally, we used microarrays to determine the global mRNA expression profiles of microdissected Purkinje cells and cellularly complex cerebellar cortex microregions. In summary, our analysis shows that cellularly complex targets lead to averaged gene expression profiles that lack substantial amounts of cell type-specific information. Thus, cell type-restricted sampling strategies are mandatory in the CNS. The combined use of a genetic label with laser-microdissection offers an unbiased approach to map patterns of gene expression onto practically any cell type of the brain
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