1,232 research outputs found

    Three dimensional imaging of short pulses

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    We exploit a slightly noncollinear second-harmonic cross-correlation scheme to map the 3D space-time intensity distribution of an unknown complex-shaped ultrashort optical pulse. We show the capability of the technique to reconstruct both the amplitude and the phase of the field through the coherence of the nonlinear interaction down to a resolution of 10 μ\mum in space and 200 fs in time. This implies that the concept of second-harmonic holography can be employed down to the sub-ps time scale, and used to discuss the features of the technique in terms of the reconstructed fields.Comment: 16 pages, 6 figure

    Collisional and molecular spectroscopy in an ultracold Bose-Bose mixture

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    The route toward a Bose-Einstein condensate of dipolar molecules requires the ability to efficiently associate dimers of different chemical species and transfer them to the stable rovibrational ground state. Here, we report on recent spectroscopic measurements of two weakly bound molecular levels and newly observed narrow d-wave Feshbach resonances. The data are used to improve the collisional model for the Bose-Bose mixture 41K87Rb, among the most promising candidates to create a molecular dipolar BEC.Comment: 13 pages, 3 figure

    Quantum dynamics of impurities in a 1D Bose gas

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    Using a species-selective dipole potential, we create initially localized impurities and investigate their interactions with a majority species of bosonic atoms in a one-dimensional configuration during expansion. We find an interaction-dependent amplitude reduction of the oscillation of the impurities' size with no measurable frequency shift, and study it as a function of the interaction strength. We discuss possible theoretical interpretations of the data. We compare, in particular, with a polaronic mass shift model derived following Feynman variational approach.Comment: 7 pages, 6 figure

    Microfluidic interactions between red blood cells and drug carriers by image analysis techniques

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    This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Blood is a complex biological fluid composed of deformable cells and platelets suspended in plasma, a protein-rich liquid. The peculiar nature of blood needs to be considered when designing a drug delivery strategy based on systemically administered carriers. Here, we report on an in vitro fluid dynamic investigation of the influence of the microcapillary flow of red blood cells (RBCs) on micron sized carriers by high speed imaging methods. The experiments were carried out in a 50μm diameter glass capillary that mimicked the hydrodynamic conditions of human microcirculation. Spherical μ particles (μ-Ps), with sizes ranging between 0.5 and 3μm, were tested. Images of the flowing RBCs and μ-Ps were acquired by a highspeed/ high-magnification microscopy. The transport and distribution of rigid particles in a suspension of RBCs under shear flow were followed for: i) the migration of RBCs towards the vessel centerline due to their deformability; ii) the cross-flow migration of μ-Ps towards the vessel wall due to their hydrodynamic interactions with RBCs; iii) the radial distribution of μ-Ps in the presence of RBCs. This study suggests that the therapeutic efficacy of μ-Ps could be ultimately affected by their interactions with the flowing RBCs in the vasculature

    The Assessment of Soil Quality of Various Age of Land Reclamation After Coal Mining: a Chronosequence Study

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    The assessment of soil quality index is one of the parameters to evaluate the goal of land reclamation. The research has been done in the various age of soil of PT Adaro Indonesia and natural forest. The research used descriptive explorative method and open field survey. Purposive sampling was used to take the sample in research location that represented the condition of every location. Principal component analysis used to know the main indicator. The main indicator was based on Eigen value >1 and chosen by indicator correlation having the highest weight index. The main indicator chosen was called minimum data set. The result of the research showed that minimum data set consisted of pH, base saturation, bulk density, electrical conductivity, cation exchange capacity, available P, total N, and soil organic carbon. The main indicators contributing to soil quality index value were total N and cation exchange capacity. Variable linear analysis showed that the longer age of land reclamation was followed by the development of soil quality index. Soil quality index in 18 years old soil reclamation (0.651) was higher than that in natural forest (0.575). Soil quality index of > 0.5 is defined as sustainable reclamation
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