1,283 research outputs found

    Experimental Test of Quantum No-Hiding Theorem

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    Linearity and unitarity are two fundamental tenets of quantum theory. Any consequence that follows from these must be respected in the quantum world. The no-cloning theorem and the no-deleting theorem are the consequences of the linearity and the unitarity. Together with the stronger no-cloning theorem they provide permanence to quantum information, thus, suggesting that in the quantum world information can neither be created nor be destroyed. In this sense quantum information is robust, but at the same time it is also fragile because any interaction with the environment may lead to loss of information. Recently, another fundamental theorem was proved, namely, the no-hiding theorem that addresses precisely the issue of information loss. It says that if any physical process leads to bleaching of quantum information from the original system, then it must reside in the rest of the universe with no information being hidden in the correlation between these two subsystems. This has applications in quantum teleportation, state randomization, private quantum channels, thermalization and black hole evaporation. Here, we report experimental test of the no-hiding theorem with the technique of nuclear magnetic resonance (NMR). We use the quantum state randomization of a qubit as one example of the bleaching process and show that the missing information can be fully recovered up to local unitary transformations in the ancilla qubits. Since NMR offers a way to test fundamental predictions of quantum theory using coherent control of quantum mechanical nuclear spin states, our experiment is a step forward in this direction.Comment: 12 pages, 6 Figs. Jharana Rani Samal, Deceased on her 27th birthday 12th Nov. 2009. The experimental work of this paper was completely carried out by the first author. We dedicate this paper to the memory of the brilliant soul of Ms. Jharana Rani Samal

    A geometric method for model reduction of biochemical networks with polynomial rate functions

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    Implementasi Pendidikan Karakter di Sekolah dan Perguruan Tinggi melalui Pembelajaran Aktif

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    Berbagai pendekatan dan metode digunakan dalam pembelajaran aktif sehingga melahirkan istilah-istilah seperti pembelajaran berpusat pada siswa (student-centered learning), pembelajaran yang diatur sendiri (self-regulated learning), pembelajaran kolaboratif (collaborative learning), pembelajaran untuk belajar (learning to learn), pembelajaran berbasis masalah (problem based learning), pembelajaran berbasis inkuiri (inquiry based learning) yang kesemuanya mengharapkan siswa terlibat secara aktif dalam pembelajaran mereka sendiri

    Deep GeMS/GSAOI near-infrared observations of N159W in the Large Magellanic Cloud

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    Aims. The formation and properties of star clusters at the edge of H II regions are poorly known, partly due to limitations in angular resolution and sensitivity, which become particularly critical when dealing with extragalactic clusters. In this paper we study the stellar content and star-formation processes in the young N159W region in the Large Magellanic Cloud. Methods. We investigate the star-forming sites in N159W at unprecedented spatial resolution using JHKs-band images obtained with the GeMS/GSAOI instrument on the Gemini South telescope. The typical angular resolution of the images is of 100 mas, with a limiting magnitude in H of 22 mag (90 percent completeness). Photometry from our images is used to identify candidate young stellar objects (YSOs) in N159W. We also determine the H-band luminosity function of the star cluster at the centre of the H II region and use this to estimate its initial mass function (IMF). Results. We estimate an age of 2 + or - 1 Myr for the central cluster, with its IMF described by a power-law with an index of gamma = - 1.05 + or - 0.2 , and with a total estimated mass of 1300 solar mass. We also identify 104 candidate YSOs, which are concentrated in clumps and subclusters of stars, principally at the edges of the H II region. These clusters display signs of recent and active star-formation such as ultra-compact H II regions, and molecular outflows. This suggests that the YSOs are typically younger than the central cluster, pointing to sequential star-formation in N159W, which has probably been influenced by interactions with the expanding H II bubble

    Exploring Foundations of Time-Independent Density Functional Theory for Excited-States

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    Based on the work of Gorling and that of Levy and Nagy, density-functional formalism for many Fermionic excited-states is explored through a careful and rigorous analysis of the excited-state density to external potential mapping. It is shown that the knowledge of the ground-state density is a must to fix the mapping from an excited-state density to the external potential. This is the excited-state counterpart of the Hohenberg-Kohn theorem, where instead of the ground-state density the density of the excited-state gives the true many-body wavefunctions of the system. Further, the excited-state Kohn-Sham system is defined by comparing it's non-interacting kinetic energy with the true kinetic energy. The theory is demonstrated by studying a large number of atomic systems.Comment: submitted to J. Chem. Phy

    Correction of distortion for optimal image stacking in Wide Field Adaptive Optics: Application to GeMS data

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    The advent of Wide Field Adaptive Optics (WFAO) systems marks the beginning of a new era in high spatial resolution imaging. The newly commissioned Gemini South Multi-Conjugate Adaptive Optics System (GeMS) combined with the infrared camera Gemini South Adaptive Optics Imager (GSAOI), delivers quasi diffraction-limited images over a field of 2 arc-minutes across. However, despite this excellent performance, some variable residues still limit the quality of the analyses. In particular, distortions severely affect GSAOI and become a critical issue for high-precision astrometry and photometry. In this paper, we investigate an optimal way to correct for the distortion following an inverse problem approach. Formalism as well as applications on GeMS data are presented.Comment: 10 pages, 6 figure

    Evaluation of FAOAqua Crop model for wheat under different irrigation regimes

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    The experiment was conducted at the research farm of the Water Technology Centre, IARI, New Delhi during rabi seasons of 2010-11and 2011-12. Irrigation treatments include irrigation applied at 50% deficit (W1) and 25 % deficit (W2) and full irrigation (W3) under recommended fertilization levels with split doses of N-fertilizer. Fullirrigation treatment was based on irrigations to meet the soil moisture deficit up to the field capacity (FC) level and deficit irrigation treatments of 25% and 50% were imposed with respect to the full irrigation.The model was calibrated with experiment generated data sets of rabi 2010-11 and validated using the data set of rabi 2011-12. It was observed that the validated model performed well for grain yield prediction with absolute prediction error of 2.9%, 0.91% and 7.85% for full, 25% deficit and 50% deficit irrigation levels, respectively. Also, for prediction of biomass yield the prediction error ranged from 11.81% to 28.96% for all three irrigation treatments. Moreover, the validated model was observed to predict the water productivity with absolute prediction errors of 43.57%, 13.87% and 12.8% for full, 25% deficit and 50% deficit irrigation treatment levels, respectively. Nonetheless, it was observed from this study that the AquaCrop model can be used to simulate the grain and biomass yield for wheat crop with acceptable accuracy under different irrigation regimes in a semi-arid enviroment
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