9 research outputs found
Quasi-probability distribution of work in a measurement-based quantum Otto engine
No full textWe study the work statistics of a measurement-based quantum Otto engine,
where quantum non-selective measurements are used to fuel the engine, in a
coupled spin working system (WS). The WS exhibits quantum coherence in the
energy eigenbasis at the beginning of a unitary work extraction stage in
presence of inter-spin anisotropic interaction. We demonstrate that the
probability of certain values of stochastic work can be negative, rendering
itself akin to the quasi-probability distribution found in phase space. This
can be attributed to the interference terms facilitated by quantum coherence.
Additionally, we establish that coherence can improve the average work in
finite time. Subsequently, we compare the work distribution with a standard QOE
operating between two heat baths. We find that, because of the absence of
quantum coherence, the probability of stochastic work cannot be negative in a
standard QOE
Anisotropy-assisted thermodynamic advantage of a local-spin thermal machine
No full textWe study quantum Otto thermal machines with a two-spin working system coupled
by anisotropic interaction. Depending on the choice of different parameters,
the quantum Otto cycle can function as different thermal machines, including a
heat engine, refrigerator, accelerator and heater. We aim to investigate how
the anisotropy plays a fundamental role in the performance of the quantum Otto
engine operating in different time scales. We find that while the efficiency of
the engine efficiency increases with the increase in anisotropy for the
quasistatic operation, quantum internal friction and incomplete thermalization
degrade the performance in a finite time cycle. Further, we study the QOE with
one of the spins, the local spin, as the working system. We show that the
efficiency of such an engine can surpass the standard quantum Otto limit, along
with maximum power, thanks to the anisotropy. This can be attributed to quantum
interference effects. We demonstrate that the enhanced performance of a
local-spin QOE originates from the same interference effects, as in a
measurement-based QOE for their finite time operation.Comment: total 14 pages, 10 figure
СРЕДСТВА СОЗДАНИЯ КОМИЧЕСКОГО В САТИРИЧЕСКИХ ЖУРНАЛАХ (НА ПРИМЕРЕ ЖУРНАЛА "ЧАЯН" ЗА 2018 ГОД)
No full textВ данной статье автор рассказывает о средствах создания комического в сатирическом татарском журнале Чаян". Автор поднимает проблему неизученности данного журнала, даже если журнал является ведущим сатирическим изданием Татарстана. Автор анализирует разные жанры, часто используемые на страницах издания и приходит к выводу, что даже через юмор можно показать ту или иную проблему общественности.In this article, the author talks about the means of creating a comic in the satirical Tatar magazine Chayan". The author raises the problem of the lack of research of this magazine, even if the magazine is the leading satirical publication of Tatarstan. The author analyzes the different genres often used on the pages of the publication and comes to the conclusion that even through humor, you can show a particular problem to the public.119-12
ReNEW: A Practical Module for Reliable Routing in Networks of Energy-Harvesting Wireless Sensors
No full textIt is a huge challenge to run IoT devices/sensors powered solely through ambient harvested energy. Since the harvested energy is less and is stochastic in nature, it is extremely challenging to achieve low latency and high reliability. To this end, we propose a distributed, energy-management module called ReNEW, using Constructive Interference (CI) to achieve our target of increased reliability, especially in the low harvesting regimes. We choose CI-based protocols to leverage low latency guarantees. Specifically, we propose a Markov-Decision model to maximize the energy utility in the infinite horizon by allocating energy optimally using a threshold-optimal policy. Since an energy scheduler is insufficient we propose distributed techniques to conserve energy on redundant nodes in the network, and dynamically activate them based on feedback. We implement ReNEW on Indriya and FlockLab testbeds for real-world scenarios in a network of 20 source nodes out of the 30 nodes. ReNEW collects data periodically with 2.5 times higher packet reception compared to LWB when the harvested energy is as low as 50μ J/s for 100B packets every 30s with a saving of 25% higher residual energy. In a nutshell, by integrating ReNEW with CI based protocols, we enable guaranteed latency and increased reliability in battery-less devices/networks.Accepted author manuscriptEmbedded System
FLeet: When time-bounded communication meets high energy-efficiency
No full textWith the advent of low-cost, embedded sensor-actuator devices, the applications of cyber-physical systems have spread multi-fold in domains like infrastructure, manufacturing, automation, etc. Wireless sensor-actuator networks (WSANs) act as the backbone for applications in these domains. Typical WSAN deployments focus on energy-efficiency (in-turn lifetime) as replacing batteries is labor intensive and expensive. However, many CPS applications require highly-reliable data delivery with strict time bounds. Unfortunately, the classical approach of scheduling/prioritizing flows for bounded time communication is hard to implement with energy-constrained embedded devices. In this work, we present FLEET, a communication primitive that guarantees timely data delivery with 1) low latency by scheduling a maximum number of end-to-end flows within a short time span; 2) highly energy-efficient networking; and 3) reliable data delivery. Using a smart parallelization technique, FLEET achieves simultaneous transmissions while guaranteeing data delivery. This reduces the average duty-cycle of the nodes and makes it more energy-efficient than many state-of-the-art protocols. By combining multiple routing strategies, FLEET not only simplifies the schedulability problem but also accommodates more flows within a time span reducing delay considerably. Overall, with respect to the state of the art, FLEET offers a delay and duty cycling reduction by 2.2 and 2.8 times, respectively.Embedded System
An Energy-Harvesting Facade Optimization System for Built Environments
No full textDaylighting is the immediate exploitation of solar energy in the form of nat-ural lighting and plays an integral role in minimizing the energy footprintof a building. Smart daylighting enables us to design buildings that providecomfort and energy savings.This work proposes a dynamic facade system for buildings which aims tomaximize user comfort while simultaneously maximizing energy savings byharvesting solar energy optimally. The solar panels on the facade can har-vest the highest amount of energy when it is positioned perpendicular to thesuns rays. However, this may result in unsatisfactory lighting conditions in-side the room and the problem is approached as a bi-objective optimizationproblem. This work is a preliminary exploration of the concept of smartskins for buildings that autonomously regulates light while harvesting solarenergy, contributing to the creation of the future of sustainable buildings.The primary focus of this research work revolves around building a con-ceptual model, formulating an optimization problem, developing a controlalgorithm, iFOS, and then evaluating it. Data was simulated using advancedsimulations to evaluate the dynamics of light indoors.Two benchmarks were created to evaluate the algorithm against, one wherethe system works towards maximizing user comfort indoors, and the other,where the system works to maximize the energy harvested by the facade.Upto 8% increase in the energy harvested was achieved with minimal loss inuser comfort in the use case evaluated. The average energy figure for TheNetherlands in the summer months is about 5 kWh/m2/day, which makesthe total energy that can be captured at 20% efficiency to be about 750kWh per day. The algorithm is found to work the best when the desiredlight level to be maintained indoors lies in the range [400,600] lux
HYDROGEN BOND MEDIATED VIBRONIC MODE MIXING AND ELECTRONIC ENERGY TRANSFER IN BENZOIC ACID DIMERS
No full textAuthor Institution: Department of Chemistry, Indian Institute of Technology KanpurFluorescence excitation, hole burning and dispersed fluorescence spectra for SVL excitations of the pure and mixed dimers of benzoic acid and 3-fluorobenzoic acid are measured in a supersonic jet expansion. The spectral analysis reveals that the vibronic modes of benzoic acid are extensively mixed with the low-frequency intermolecular modes of the dihydrogen bonded interface, and the mixing is sensitive to the position of the fluorine substitution at the aromatic ring and overall symmetry of the conformers. In case of the mixed dimer, three electronic origin bands are identified corresponding to excitations of the benzoic acid and two conformers of 3-fluorobenzoic acid moieties, and the former is about 700 wavenumbers higher in energy that the latter two. Partial transfer of electronic energy is observed when the electronic origin of the benzoic acid moiety is excited state, and this occurs even there is no visible overlap between the emission spectrum of the donor and absorption spectra of the acceptor moieties. The spectra of different dimeric species will be presented and the role of hydrogen bonds in energy transfer process will be discussed
The management of irregular migration in Thailand: Thainess, identity and citizenship
No full textThis PhD analyses and investigates, from a historical perspective, the way in which Thailand has dealt with different groups of migrant populations, and how this
reflects the current dichotomy between legal and illegal migrants in contemporary Thai policies regarding irregular migration management. It is argued that these policies reflect notions of `Thainess, ' citizenship, race and ethnicity, the question of identities and issues related to inclusion/exclusion of the migration populations
within the structure of Thai society. This thesis also examines how Thailand's policies in irregular migration management reflect the economic and political interests of the government and employers.
This thesis also focuses on the recent Greater Mekong subregional economic cooperation and integration policies, by investigating how these policies will resolve
or intensify the problems concerning the management of migrant workers, as well as other problems relating to human rights violations, and various forms of
discrimination towards the migrant population in Thailand.
The concept and construction of `Thainess' is critically analysed with the purpose of throwing light on the changes in migration management policies, and the related
regulations and practices. This analysis enables us to examine and capture how the dynamism and fluidity of `Thainess' varies through time, locality and economic
status. It also explores how notions of Thai identity influence the ways in which policies on immigration and citizenship are constructed
Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo
No full textInternational audienceIntermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M⊙, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M⊙ providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M⊙ and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.Key words: gravitational waves / stars: black holes / black hole physicsCorresponding author: W. Del Pozzo, e-mail: [email protected]† Deceased, August 2020
