Entanglement enhances cooling in microscopic quantum fridges

Small self-contained quantum thermal machines function without external source of work or control, but using only incoherent interactions with thermal baths. Here we investigate the role of entanglement in a small self-contained quantum refrigerator. We first show that entanglement is detrimental as far as efficiency is concerned---fridges operating at efficiencies close to the Carnot limit do not feature any entanglement. Moving away from the Carnot regime, we show that entanglement can enhance cooling and energy transport. Hence a truly quantum refrigerator can outperform a classical one. Furthermore, the amount of entanglement alone quantifies the enhancement in cooling.Comment: 7 pages, 3 figure

Unifying paradigms of quantum refrigeration: fundamental limits of cooling and associated work costs

In classical thermodynamics the work cost of control can typically be neglected. On the contrary, in quantum thermodynamics the cost of control constitutes a fundamental contribution to the total work cost. Here, focusing on quantum refrigeration, we investigate how the level of control determines the fundamental limits to cooling and how much work is expended in the corresponding process. \jona{We compare two extremal levels of control. First coherent operations, where the entropy of the resource is left unchanged, and second incoherent operations, where only energy at maximum entropy (i.e. heat) is extracted from the resource. For minimal machines, we find that the lowest achievable temperature and associated work cost depend strongly on the type of control, in both single-cycle and asymptotic regimes. We also extend our analysis to general machines.} Our work provides a unified picture of the different approaches to quantum refrigeration developed in the literature, including algorithmic cooling, autonomous quantum refrigerators, and the resource theory of quantum thermodynamics.Comment: 17 + 28 pages, 10 figure

The home environment and maternal alienation: their relationship with the social development of children

Call number: LD2668 .T4 1985 E22Master of Scienc

Diverse Spectrum of Presentation of Coronary Slow Flow Phenomenon: A Concise Review of the Literature

The coronary slow flow phenomenon (CSFP) is a disease entity characterized by slow progression of angiographic contrast in the coronary arteries in the absence of stenosis in the epicardial vessels. CSFP has a diverse presentation from mild chest discomfort to ST-segment elevation myocardial infarction. It can also have severe morbidity and mortality implications and can significantly hamper the quality of life of those affected. In this paper we present two patients with CSFP highlighting the diverse spectrum of presentation. A concise review of the literature is also provided emphasizing the epidemiology, pathogenesis, diagnostic parameters, treatment modalities, and clinical significance of this phenomenon

Municipality of Anchorage Baseline Greenhouse Gas Emissions Inventory Base Year 2008

The Municipality of Anchorage (MOA) conducted a greenhouse gas (GHG) emissions inventory with a 2008 base year in order to quantify the results of initiatives to reduce the MOA’s current carbon footprint, place those initiatives into a broader strategic plan, and measure reductions going forward. The MOA conducted the carbon baseline because it is a signatory of the U.S. Mayors Climate Protection Agreement. Over 710 U.S. Mayors have signed the agreement. Under the agreement, Anchorage must attempt to meet or beat the Kyoto Protocol targets of 7% reduction from 1990 levels by 2012, encourage their state governments and federal government to meet or beat the Kyoto Protocol targets, and urge the U.S. Congress to pass greenhouse gas reduction legislation establishing a national emissions trading system. The greenhouse gas emissions inventory is the first step for Anchorage to begin measuring the reductions of greenhouse gases as the MOA strives to meet the 7% reduction goal by 2012. The MOA chose to adopt the framework developed by the Local Governments for Sustainability (ICLEI) for measuring progress toward reduction goals because of its wide use, standardized methodology, and proven results. The ICLEI strategy has been adopted worldwide by over 1,000 communities working toward meet Kyoto Protocol carbon emission reduction targets.Municipality of Anchorag

IDENTIFYING LIMITS OF SCALABILITY IN DISTRIBUTED, HETEROGENEOUS, LAYER BASED MONITORING CONCEPTS LIKE SLAte

In this paper we present the concept of a scalable job centric monitoring infrastructure.The overall performance of this distributed, layer based architecturecalled SLAte can be increased by installing additional servers to adapt to thedemands of the monitored resources and users. Another important aspect is tooffer a uniform global view on all data which are stored distributed to providean easy access for users or visualisation tools. Additionally we discus the impactof these uniform access layer on scalability

Hierarchical Sticker and Sticky Chain Dynamics in Self-Healing Butyl Rubber Ionomers

We present a detailed comparison of the microscopic dynamics and the macroscopic mechanical behavior of novel butyl rubber ionomers with tunable dynamics of sparse sticky imidazole-based sidegroups that form clusters of about 20 units separated by essentially unperturbed chains. This material platform shows promise for application as self-healing elastomers. Size and thermal stability of the ionic clusters were probed by small-angle X-ray scattering, and the chain and sticker dynamics were studied by a combination of broadband dielectric spectroscopy (BDS) and advanced NMR methods. The results are correlated with the rheological behavior characterized by dynamic-mechanical analysis (DMA). While the NMR-detected chain relaxation and DMA results agree quantitatively and confirm relevant aspects of the sticky-reptation picture on a microscopic level, we stress and explain that apparent master curves are of limited use for such a comparison. The cluster-related relaxation time detected by BDS is much shorter than the elastic chain relaxation time, although the weak conductivity does follow the latter. The systematic trends across the sample series suggest that all relaxations are dominated by a cluster-related activation barrier, but also that the BDS-based cluster relaxation does not seem to be directly associated with the effective sticker lifetime. Nonlinear stress-strain experiments demonstrate a reduction of sticker lifetime on stretching and that the stored stress and the elastic recovery depend on the deformation rate. © 2019 American Chemical Society

Hierarchical Sticker and Sticky Chain Dynamics in Self-Healing Butyl Rubber Ionomers

We present a detailed comparison of the microscopic dynamics and the macroscopic mechanical behavior of novel butyl rubber ionomers with tunable dynamics of sparse sticky imidazole-based sidegroups that form clusters of about 20 units separated by essentially unperturbed chains. This material platform shows promise for application as self-healing elastomers. Size and thermal stability of the ionic clusters were probed by small-angle X-ray scattering, and the chain and sticker dynamics were studied by a combination of broadband dielectric spectroscopy (BDS) and advanced NMR methods. The results are correlated with the rheological behavior characterized by dynamic-mechanical analysis (DMA). While the NMR-detected chain relaxation and DMA results agree quantitatively and confirm relevant aspects of the sticky-reptation picture on a microscopic level, we stress and explain that apparent master curves are of limited use for such a comparison. The cluster-related relaxation time detected by BDS is much shorter than the elastic chain relaxation time, although the weak conductivity does follow the latter. The systematic trends across the sample series suggest that all relaxations are dominated by a cluster-related activation barrier, but also that the BDS-based cluster relaxation does not seem to be directly associated with the effective sticker lifetime. Nonlinear stress-strain experiments demonstrate a reduction of sticker lifetime on stretching and that the stored stress and the elastic recovery depend on the deformation rate. © 2019 American Chemical Society