8,297 research outputs found
Probing charge fluctuator correlations using quantum dot pairs
We study a pair of quantum dot exciton qubits interacting with a number of
fluctuating charges that can induce a Stark shift of both exciton transition
energies. We do this by solving the optical master equation using a numerical
transfer matrix method. We find that the collective influence of the charge
environment on the dots can be detected by measuring the correlation between
the photons emitted when each dot is driven independently. Qubits in a common
charge environment display photon bunching, if both dots are driven on
resonance or if the driving laser detunings have the same sense for both
qubits, and antibunching if the laser detunings have in opposite signs. We also
show that it is possible to detect several charges fluctuating at different
rates using this technique. Our findings expand the possibility of measuring
qubit dynamics in order to investigate the fundamental physics of the
environmental noise that causes decoherence.Comment: 9 pages, 13 figure
Structural Adjustment and the Health Care Sector in India: some policy issues in financing
The paper examines different strategies for the financing of health care in India, where the effect of structural adjustment has been to undermine the traditional resource base. The relative merits of user fees, insurance schemes, administrative decentralisation and partial privatisation are discussed. The main policy conclusion is the need for better regulation of the various modalities of health care delivery.
Systemic Therapy in Endometrial Cancer: Recent Advances.
Endometrial cancer is a chemosensitive disease. Studies have established a clear benefit of chemotherapy in advanced stages and trials are ongoing to define its role in early stages as well. As more molecular pathways are being elucidated there is increasing role for targeted agents and future looks quite promising. We did an extensive search both online and offline for all the relevant articles including chemotherapy and targeted therapy for endometrial cancer
Future fuels and engines for railroad locomotives. Volume 1: Summary
The potential for reducing the dependence of railroads on petroleum fuel, particularly Diesel No. 2 was investigated. Two approaches are studied: (1) to determine how the use of Diesel No. 2 can be reduced through increased efficiency and conservation, and (2) to use fuels other than Diesel No. 2 both in Diesel and other types of engines. Because synthetic hydrocarbon fuels are particularly suited to medium speed diesel engines, the first commercial application of these fuels may be by the railroad industry
Assessment of alumina nano fluid as a coolant in double pipe gas cooler for trans-critical CO2 refrigeration cycle
In this study, the performance of an alumina nanofluid cooled double pipe gas cooler fortrans-critical C02 refrigeration cycle is theoretically compared to that of water cooled gas cooler. Equal pumping power comparison criterion is adopted besides conventional equal Reynolds number comparison base. Nanofluid is loaded with 0.5%, 1.5% and 2.5% of particle volume fraction under turbulent flow conditions. Drastic variation of thermal and transport properties of CO2 in the vicinity of pseudo criticai temperature is taken care of by employing an appropriate discretization technique. Effect of gas cooler pressure, Reynolds number, pumping power and nanoparticle volume fraction on COP of refrigeration system, gas cooler overall conductance, effectiveness and its capacity has been studied. Results indicate that at equal Reynolds number comparison, performance for alumina nanofluid cooled system is better than that of water cooled system. On the other hand, at equal pumping power comparison basis, the performance of water cooled
system is superior. Even at equal mass flow rate comparison criterion, the performance of nanofluid cooled system degrades with increase in particle volume fraction. This study is expected to help to assess the nano fluid as a coolant before expensive experimentation
Modelling Tensile Behaviour of Stir-cast Aluminium Matrix Composites (AMCs) Using Factorial Design of Experiments
Aluminium based metal matrix composites (MMCs) with ceramic reinforcement are finding extensive applications in aerospace, automobile, agricultural farm machinery and other areas which demand combination of properties such as high strength, stiffness, wear resistance, high temperature resistance, etc. In particular, components comprising Al7075 alloy matrix, reinforced with alumina (Al2O3) particulates, are reported to excel their monolithic counterparts. Liquid metal route and powder metallurgy are the most widely used fabrication techniques to produce these MMCs. The former has advantages such as easy adaptability, low cost and possibility of subjecting the cast components to secondary processes like forging, rolling and extrusion for producing the final components. This paper presents the details of developing a mathematical model to predict the tensile behavior like ultimate tensile strength (UTS) and percentage elongation of the as-cast Al7075/Al2O3 in terms of size and % fraction of Al2O3, holding temperature and holding time; using factorial design of experiments (DoE). Adequacy of the models was tested using Fisher's F-test. UTS of the composite was increased by 20%compared to that of matrix and % elongation was reduced by around 30%. Keywords: MMC, UTS, % elongation, Design of experiments, Modelling
Mobility of twin and phase boundaries
This paper reviews some recent advances in understanding the mobility of twin and phase boundaries in martensites, and discusses the design of systematic experiments
Evolution of Conversations in the Age of Email Overload
Email is a ubiquitous communications tool in the workplace and plays an
important role in social interactions. Previous studies of email were largely
based on surveys and limited to relatively small populations of email users
within organizations. In this paper, we report results of a large-scale study
of more than 2 million users exchanging 16 billion emails over several months.
We quantitatively characterize the replying behavior in conversations within
pairs of users. In particular, we study the time it takes the user to reply to
a received message and the length of the reply sent. We consider a variety of
factors that affect the reply time and length, such as the stage of the
conversation, user demographics, and use of portable devices. In addition, we
study how increasing load affects emailing behavior. We find that as users
receive more email messages in a day, they reply to a smaller fraction of them,
using shorter replies. However, their responsiveness remains intact, and they
may even reply to emails faster. Finally, we predict the time to reply, length
of reply, and whether the reply ends a conversation. We demonstrate
considerable improvement over the baseline in all three prediction tasks,
showing the significant role that the factors that we uncover play, in
determining replying behavior. We rank these factors based on their predictive
power. Our findings have important implications for understanding human
behavior and designing better email management applications for tasks like
ranking unread emails.Comment: 11 page, 24th International World Wide Web Conferenc
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