412 research outputs found

    Observation of near-quantum-limited velocity distributions of a levitated particle

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    We demonstrate time-of-flight measurements for an ultracold levitated nanoparticle and reveal its translational velocity in the quantum regime. We discover that the velocity distributions obtained with repeated measurements are significantly broadened via librational motions of the nanoparticle. Under feedback cooling on all the librational motions, we recover the velocity distributions in reasonable agreement with an expectation from the occupation number, with approximately twice the width of the quantum limit. The strong impact of librational motions on the translational motions is understood as a result of the deviation between the libration center and the center of mass, induced by the asymmetry of the nanoparticle. Our results elucidate the importance of the control over librational motions and establish the basis for exploring quantum mechanical properties of levitated nanoparticles in terms of their velocity.Comment: 7 pages, 7 file

    Central mode and soft mode behavior in PbMg1/Nb2/3O3 relaxor ferroelectric

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    The relaxor ferroelectric PbMg1/Nb2/3O3 was investigated by means of broad-band dielectric and Fourier Transform Infrared (FTIR) transmission spectroscopy in the frequency range from 1 MHz to 15 THz at temperatures between 20 and 900 K using PMN films on infrared transparent sapphire substrates. While thin film relaxors display reduced dielectric permittivity at low frequencies, their high frequency intrinsic or lattice response is shown to be the same as single crystal/ceramic specemins. It was observed that in contrast to the results of inelastic neutron scattering, the optic soft mode was underdamped at all temperatures. On heating, the TO1 soft phonon followed the Cochran law with an extrapolated critical temperature equal to the Burns temperature of 670 K and softened down to 50 cm-1. Above 450 K the soft mode frequency leveled off and slightly increased above the Burns temperature. A central mode, describing the dynamics of polar nanoclusters appeared below the Burns temperature at frequencies near the optic soft mode and dramatically slowed down below 1 MHz on cooling below room temperature. It broadened on cooling, giving rise to frequency independent losses in microwave and lower frequency range below the freezing temperature of 200 K. In addition, a new heavily damped mode appeared in the FTIR spectra below the soft mode frequency at room temperature and below. The origin of this mode as well as the discrepancy between the soft mode damping in neutron and infrared spectra is discussed.Comment: 7 pages with 7 figures, submitted to Phys. Rev.

    Biocompatibility of bio based calcium carbonate nanocrystals aragonite polymorph on NIH 3T3 fibroblast cell line

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    Background: Currently, there has been extensive research interest for inorganic nanocrystals such as calcium phosphate, iron oxide, silicone,carbon nanotube and layered double hydroxide as a drug delivery system especially in cancer therapy. However, toxicological screening of suchparticles is paramount importance before use as delivery carrier. In this study we examine the biocompatibility of CaCO3 nanocrystal on NIH 3T3cell line.Material and Methods: Transmission and field emission scanning electron microscopy (TEM and FESEM) were used for the characterisation ofCaCO3 nanocrystals. Cytotoxicity and genotoxic effect of calcium carbonate nanocrystals in cultured mouse embryonic fibroblast NIH 3T3 cellline using various bioassays including MTT, and Neutral red/Trypan blue double-staining assays. LDH, BrdU and reactive oxygen species wereused for toxicity analysis. Cellular morphology was examined by scanning electron microscopy (SEM) and confocal fluorescence microscope.Results: The outcome of the analyses revealed a clear rod-shaped aragonite polymorph of calcium carbonate nanocrystal. The analysed cytotoxic and genotoxicity of CaCO3 nanocrystal on NIH 3T3 cells using different bioassays revealed no significance differences as compared to control. A slight decrease in cell viability was noticed when the cells were exposed to higher concentrations of 200 to 400 ìg/ml, while increase in ROS generation and LDH released at 200 and 400 ìg/ml was observed.Conclusions: The study has shown that CaCO3 nanocrystal is biocompatible and non toxic to NIH 3T3 fibroblast cells. The analysed results offer a promising potential of CaCO3 nanocrystal for the development of  intracellular drugs, genes and other macromolecule delivery systems.Keywords: Biocompatibility; Calcium carbonate; nanocrystals; drugs and Cockle shells

    Trajectory Optimization of Quadrotor-UAV Drone Using Genetic Algorithm

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    Unmanned Aerial Vehicles (UAVs) Technology recently attracts attention of many researchers; this is due toits numerous potentialities in civil application. One of the key areas of interest by researches is how to achievea total talent of “Sense and Avoid” in the UAV which will enhance safe and efficient trajectory of the vehicle.This is why this paper is going to use an optimization technique to optimize trajectory path of the UAV flight.The chosen optimization algorithm is Genetic algorithm (GA) which is going to be use to optimize the trajectoryof UAV by determine the shortest path of flight as well as obstacle-free path in order to save energy and timeduring flight. MATLAB and Simulink are used to simulate as well as evaluate the algorithm. In the result fromthe experiment, it appeared that an optimized trajectory path is tremendously better than path from the firstrandomly generated population in term of distance covered as well as time taken before triumph the target pointfrom the initial point

    Optimization of Marriage Registration as Legal Certainty of Children's Rights in the Perspective of Maqasid Shariah

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    Problems in the household are always related to children. Children are the most significant mandate from Allah SWT. They must be cared for and protected even if they get into legal problems. Marriage registration is a form of legal certainty for children’s rights. Often children do not get the fulfillment of their rights due to the actions of their parents. The rise of unregistered marriages is one of the reasons why the legal certainty of children’s rights is questioned. The legal consequences of unregistered marriages create new problems for children, incredibly fulfilling their rights. Therefore, it is necessary to optimize the registration of this marriage for the future of the family, especially the children. Of course, optimizing marriage registration is inseparable from the participation of related parties. It requires synergy between the government, the Office of Religious Affairs (KUA), the Population and Civil Registration Service (DISDUKCAPIL), and the community. Marriage registration is essential, especially from the legal aspect, both in positive and Islamic law. Because basically, Islamic law does not oblige every marriage contract, but marriage registration is essential from the point of view of its benefits. This research belongs to empirical juridical research, using primary, secondary, and tertiary data collection techniques. This study uses a case approach and data analysis techniques used descriptively. The results of the discussion in this study found that marriage registration is beneficial for couples in terms of Islamic law and positive law; not just administration but providing legal certainty to wives, especially children born in terms of child status, education, and inheritance rights. Gorontalo Province marriage registration by the KUA and Disdukcapil has been running optimally even though the data found in unregistered marriages are pretty high, and this is because people do not understand the importance of marriage registration. Keywords: optimization, marriage registration, legal certainty, Maqasid Sharia
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