935 research outputs found
Simulation of mirror inversion of quantum states in an XY spin chain using NMR
We report an experimental quantum simulation of unitary dynamics of an XY
spin chain with pre-engineered couplings. Using this simulation, we demonstrate
the mirror inversion of quantum states, proposed by Albanese et al. [Phys. Rev.
Lett. 93, 230502 (2004)]. The experiment is performed with a 5-qubit dipolar
coupled spin system using nuclear magnetic resonance techniques. To perform
quantum simulation we make use of the recently proposed unitary operator
decomposition algorithm of Ajoy et al. [Phys. Rev. A 85, 030303 (2012)] along
with numerical pulse optimization techniques. Further, using mirror inversion,
we demonstrate that entangled states can be transferred from one end of the
chain to the other end. The simulations are implemented with high experimental
fidelity, which implies that these kind of simulations may be possible in
larger systems.Comment: 9 pages, 6 figure
Violation of Entropic Leggett-Garg Inequality in Nuclear Spins
We report an experimental study of recently formulated entropic Leggett-Garg
inequality (ELGI) by Usha Devi et al. (arXiv: 1208.4491v2 (2012)). This
inequality places a bound on the statistical measurement outcomes of dynamical
observables describing a macrorealistic system. Such a bound is not necessarily
obeyed by quantum systems, and therefore provides an important way to
distinguish quantumness from classical behavior. Here we study ELGI using a
two-qubit nuclear magnetic resonance system. To perform the noninvasive
measurements required for the ELGI study, we prepare the system qubit in a
maximally mixed state as well as use the `ideal negative result measurement'
procedure with the help of an ancilla qubit. The experimental results show a
clear violation of ELGI by over four standard deviations. These results agree
with the predictions of quantum theory. The violation of ELGI is attributed to
the fact that certain joint probabilities are not legitimate in the quantum
scenario, in the sense they do not reproduce all the marginal probabilities.
Using a three-qubit system, we experimentally demonstrate that three-time joint
probabilities do not reproduce certain two-time marginal probabilities.Comment: 5 pages, 5 figures, 1 page supplementar
Belching on exertion - coronary artery disease
Belching is a ubiquitous symptom in clinical practice. It could be due to gastrointestinal disease or behavioral, functional and physiological causes. It’s association with acute myocardial infarction, more frequently, with inferior myocardial infarction, has been well established. But exertional belching as a cardinal symptom of coronary artery disease is not well documented and its presence is not mentioned in any standard textbooks. It is rarely reported in the literature. Here we present a female diabetic, who presented with exertional belching as a lone complaint. She was confirmed to have significant coronary artery disease necessitating an intervention. So it may be prudent if clinicians are aware of the fact that exertional belching could be of cardiac origin and needs further evaluation and intervention
Invention into the AC Voltage Regulator with V/F Technique for Induction Motor Starting Applications
Modern electrical motors are available in many different forms with different mounting arrangements. To ensure a long life for the motor it is important to select it with correct degree of protection when operating under heavy duty conditions in a severe environment. Smooth starting is also one of major considerations to get long life and optimum efficiency. The conventional method to start an asynchronous motor with a soft starter is by reducing the voltage of the motor by varying the voltage “off time”. The “off time” could for example be controlled to achieve a desired maximum current level or a constant driving torque. Even if the voltage is reduced the fundamental frequency of the voltage is equal to the supply voltage frequency. That gives a large difference between angular speed of supply voltage and angular speed of the rotor during start. Due to the large difference in angular speed the motor flux will be low and thereby also the ability to produce torque. Instead of using the conventional control method with a reduced voltage it is possible to use a method with controlled flux similar to frequency inverters for soft-starters. As the soft-starter does not have the intermediate DC energy storage the applied voltage vector has to be directly modulated from the mains supply
A strategic approach for preparation of oxide nanomaterials
A microwave assisted solvothermal method is described for rapid preparation of nano-oxides. This method is based on exploiting differential dielectric constants to induce preferred heating and decomposition of the oxide precursors in the presence of suitable capping agents. This strategic approach has been used to prepare nanopowders of MgO, NiO, ZnO, Al2O3, Fe2O3 and ZrO2
Multi-dimensional parametric assessment with IoT in acquaintance of digital pipeline
In IoT researches are found millions of devices are connected in global digital infrastructure framed in network fashion. Most of the things on the network use cloud or central database to share their data and control signals to control and manage the devices on the IoT network. Devices on the network need fast traversing paths, to take correct decision in right time. The data synchronization between source and destination is very important in real time parameter maintenance. The multidimensional parametric evaluation of the environment or the surrounding area is facing problems with data synchronization and congestion in the sensor network. This will lead arrival of fault data at the destination. The fault data also leads a misconception at user end. In the present work pipeline integration is proposed to overcome the misconception and synchronization failures. The pipeline and Arduino UNO processor are integrated on Proteus simulation tool. Transducer nodes and the functionalities are analysed with pipeline
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