1,509 research outputs found

    Formulasi Sediaan Granul Mukoadhesif Kombinasi Ekstrak Kulit Batang Mimba (Azadirachta Indica a. Juss) Dan Kunyit (Curcuma Domestica Val.)

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    Neem bark (Azadirachta indica A.Juss) and turmeric (Curcuma domestica Val.) extracts have been found posses gastroprotective effect so that they are used in the treatment of gastric ulcer. Administration of combination of both extracts can give synergistic effect so that the administration dose can be reduced. In this research, combination of neem bark and turmeric extracts were formulated as mucoadhesive granules to improve their effectivenesses by increasing the residence time of dosage form in the stomach. Mucoadhesive granuleswere prepared by wet granulation method in six formulas using HPMC, Carbopol, and combination of HPMC and Carbopol as mucoadhesive polymers. Granules were evaluated for particle size distribution, swelling, mucoadhesive strength with bioadhesive in vitro test and wash off test, and dissolution. Bioadhesive in vitro test showed that all formulas have goodmucoadhesive strength.Wash off test showed that combination of HPMC and Carbopol can improve mucoadhesive strength of formulas. Mucoadhesive strength increased with the increasing of HPMC. The result of this research indicated that formula with combination ofHPMCand Carbopol (2:1) showed best mucoadhesive strength with percentage of mucoadhesion 98.67%in bioadhesive in vitro test and 38.00% in wash off test

    Correlation of conductivity and angle integrated valence band photoemission characteristics in single crystal iron perovskites for 300 K < T < 800 K: Comparison of surface and bulk sensitive methods

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    A single crystal monolith of La0.9Sr0.1FeO3 and thin pulsed laser deposited film of La0.8Sr0.2Fe0.8Ni0.2O3 were subject to angle integrated valence band photoemission spectroscopy in ultra high vacuum and conductivity experiments in ambient air at temperatures from 300 K to 800 K. Except for several sputtering and annealing cycles, the specimen were not prepared in-situ.. Peculiar changes in the temperature dependent, bulk representative conductivity profile as a result of reversible phase transitions, and irreversible chemical changes are semi-quantitatively reflected by the intensity variation in the more surface representative valence band spectra near the Fermi energy. X-ray photoelectron diffraction images reflect the symmetry as expected from bulk iron perovskites. The correlation of spectral details in the valence band photoemission spectra (VB PES) and details of the conductivity during temperature variation suggest that valuable information on electronic structure and transport properties of complex materials may be obtained without in-situ preparation

    Direct Observation of High-Temperature Polaronic Behavior In Colossal Magnetoresistive Manganites

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    The temperature dependence of the electronic and atomic structure of the colossal magnetoresistive oxides La1xSrxMnO3La_{1-x}Sr_{x}MnO_{3} (x = 0.3, 0.4) has been studied using core and valence level photoemission, x-ray absorption and emission, and extended x-ray absorption fine structure spectroscopy. A dramatic and reversible change of the electronic structure is observed on crossing the Curie temperature, including charge localization and spin moment increase of Mn, together with Jahn-Teller distortions, both signatures of polaron formation. Our data are also consistent with a phase-separation scenario.Comment: 5 pages, 4 figures, revte

    Managing Risk of Bidding in Display Advertising

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    In this paper, we deal with the uncertainty of bidding for display advertising. Similar to the financial market trading, real-time bidding (RTB) based display advertising employs an auction mechanism to automate the impression level media buying; and running a campaign is no different than an investment of acquiring new customers in return for obtaining additional converted sales. Thus, how to optimally bid on an ad impression to drive the profit and return-on-investment becomes essential. However, the large randomness of the user behaviors and the cost uncertainty caused by the auction competition may result in a significant risk from the campaign performance estimation. In this paper, we explicitly model the uncertainty of user click-through rate estimation and auction competition to capture the risk. We borrow an idea from finance and derive the value at risk for each ad display opportunity. Our formulation results in two risk-aware bidding strategies that penalize risky ad impressions and focus more on the ones with higher expected return and lower risk. The empirical study on real-world data demonstrates the effectiveness of our proposed risk-aware bidding strategies: yielding profit gains of 15.4% in offline experiments and up to 17.5% in an online A/B test on a commercial RTB platform over the widely applied bidding strategies

    Thermal expansion and magnetostriction of pure and doped RAgSb2 (R = Y, Sm, La) single crystals

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    Data on temperature-dependent, anisotropic thermal expansion in pure and doped RAgSb2 (R = Y, Sm, La) single crystals are presented. Using the Ehrenfest relation and heat capacity measurements, uniaxial pressure derivatives for long range magnetic ordering and charge density wave transition temperatures are evaluated and compared with the results of the direct measurements under hydrostatic pressure. In-plane and c-axis pressure have opposite effect on the phase transitions in these materials, with in-plane effects being significantly weaker. Quantum oscillations in magnetostriction were observed for the three pure compounds, with the possible detection of new frequencies in SmAgSb2 and LaAgSb2. The uniaxial (along the c-axis) pressure derivatives of the dominant extreme orbits (beta) were evaluated for YAgSb2 and LaAgSb2

    Elastic constants of borocarbides. New approach to acoustic Measurement technique

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    A new version of the phase method of determining the sound velocity is proposed and implemented. It utilizes the ``Nonius'' measurement technique and can give acceptable accuracy (~1%) in samples of submillimeter size. Measurements of the sound velocity are made in single-crystal samples of the borocarbides RNi2B2C (R = Y,Lu,Ho). The elastic constants and the Debye temperature are calculated.Comment: 5 figures, 2 table

    Missed prediction of the neutron halo in 37^{37}Mg

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    Halo phenomena have long been an important frontier in both experimental and theoretical nuclear physics. 37^{37}Mg was identified as a halo nucleus in 2014 and remains the heaviest nuclear halo system to date. While the halo phenomenon in 37^{37}Mg was not predicted before the discovery, its description has been still challenging afterwards. In this Letter, we report a microscopic, self-consistent, and density-functional independent description of the neutron halo in 37^{37}Mg by the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) that was developed in 2010. The experimental neutron separation energies and empirical matter radii of neutron-rich magnesium isotopes as well as the deformed pp-wave halo characteristics of 37^{37}Mg are well reproduced without any free parameters. The DRHBc theory investigated only even-even magnesium isotopes in previous works and for that reason missed predicting 37^{37}Mg as a halo nucleus before 2014. Although the core and the halo of 37^{37}Mg are both prolate, higher-order shape decoupling on the hexadecapole and hexacontatetrapole levels is predicted.Comment: 8 pages, 4 figures, 1 tabl

    Fragile antiferromagnetism in the heavy-fermion compound YbBiPt

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    We report results from neutron scattering experiments on single crystals of YbBiPt that demonstrate antiferromagnetic order characterized by a propagation vector, τAFM\tau_{\rm{AFM}} = (121212\frac{1}{2} \frac{1}{2} \frac{1}{2}), and ordered moments that align along the [1 1 1] direction of the cubic unit cell. We describe the scattering in terms of a two-Gaussian peak fit, which consists of a narrower component that appears below TN 0.4T_{\rm{N}}~\approx 0.4 K and corresponds to a magnetic correlation length of ξn\xi_{\rm{n}} \approx 80 A˚\rm{\AA}, and a broad component that persists up to TT^*\approx 0.7 K and corresponds to antiferromagnetic correlations extending over ξb\xi_{\rm{b}} \approx 20 A˚\rm{\AA}. Our results illustrate the fragile magnetic order present in YbBiPt and provide a path forward for microscopic investigations of the ground states and fluctuations associated with the purported quantum critical point in this heavy-fermion compound.Comment: 5 pages, 3 figure
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