1,408 research outputs found
Toward quantum processing in molecules: A THz-bandwidth coherent memory for light
The unusual features of quantum mechanics are enabling the development of
technologies not possible with classical physics. These devices utilize
nonclassical phenomena in the states of atoms, ions, and solid-state media as
the basis for many prototypes. Here we investigate molecular states as a
distinct alternative. We demonstrate a memory for light based on storing
photons in the vibrations of hydrogen molecules. The THz-bandwidth molecular
memory is used to store 100-fs pulses for durations up to 1ns, enabling 10,000
operational time bins. The results demonstrate the promise of molecules for
constructing compact ultrafast quantum photonic technologies.Comment: 5 pages, 3 figures, 1 tabl
Storage and retrieval of ultrafast single photons using a room-temperature diamond quantum memory
We report the storage and retrieval of single photons, via a quantum memory,
in the optical phonons of room-temperature bulk diamond. The THz-bandwidth
heralded photons are generated by spontaneous parametric downconversion and
mapped to phonons via a Raman transition, stored for a variable delay, and
released on demand. The second-order correlation of the memory output is
, demonstrating preservation of non-classical
photon statistics throughout storage and retrieval. The memory is low-noise,
high-speed and broadly tunable; it therefore promises to be a versatile
light-matter interface for local quantum processing applications.Comment: 6 pages, 4 figure
Ultrasound-induced acoustophoretic motion of microparticles in three dimensions
We derive analytical expressions for the three-dimensional (3D)
acoustophoretic motion of spherical microparticles in rectangular
microchannels. The motion is generated by the acoustic radiation force and the
acoustic streaming-induced drag force. In contrast to the classical theory of
Rayleigh streaming in shallow, infinite, parallel-plate channels, our theory
does include the effect of the microchannel side walls. The resulting
predictions agree well with numerics and experimental measurements of the
acoustophoretic motion of polystyrene spheres with nominal diameters of 0.537
um and 5.33 um. The 3D particle motion was recorded using astigmatism particle
tracking velocimetry under controlled thermal and acoustic conditions in a
long, straight, rectangular microchannel actuated in one of its transverse
standing ultrasound-wave resonance modes with one or two half-wavelengths. The
acoustic energy density is calibrated in situ based on measurements of the
radiation dominated motion of large 5-um-diam particles, allowing for
quantitative comparison between theoretical predictions and measurements of the
streaming induced motion of small 0.5-um-diam particles.Comment: 13 pages, 8 figures, Revtex 4.
The double challenge of AFF
This paper explores the present status and future options of a Norwegian management consultancy company, AFF, with respect to serving Norwegian multinational enterprises (MNEs). The case of AFF is also employed to illustrate challenges and options facing similar consultancy firms. We argue that AFF and domestic management consultancies aiming to serve contemporary MNEs are confronted by two main challenges. The first is to respond to the evolution of its clients into MNEs that are dependent on effective knowledge sharing across their international operations. The second, related challenge is that contemporary organizations are demanding a new wave of consultancy services focusing management of boundary spanning processes. The paper argues that the development of dynamic capabilities is essential both for AFF and for consultancies facing similar challenges
Detecting Atlantic herring by parametric sonar
Author Posting. © Acoustical Society of America, 2010. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 127 (2010): EL153-EL159, doi:10.1121/1.3336398.The difference-frequency band of the Kongsberg TOPAS PS18 parametric sub-bottom profiling sonar, nominally 1–6 kHz, is being used to observe Atlantic herring. Representative TOPAS echograms of herring layers and schools observed in situ in December 2008 and November 2009 are presented. These agree well with echograms of volume backscattering strength derived simultaneously with the narrowband Simrad EK60/18- and 38-kHz scientific echo sounder, also giving insight into herring avoidance behavior in relation to survey vessel passage. Progress in rendering the TOPAS echograms quantitative is described.Work supported by the Norwegian Research Council under Grant No. 184705 and the Office of
Naval Research under Award No. N000140910482
Treatment with Unlabeled mAb BR96 After Radioimmunotherapy with (177)Lu-DOTA-BR96 in a Syngeneic Rat Colon Carcinoma Model.
Metastatic disease after successful treatment of the primary tumor continues to be a therapeutic challenge. Enhancement of therapeutic effects by the administration of unlabeled monoclonal antibodies (mAbs) after radioimmunotherapy (RIT) may provide a means of preventing or delaying the development of metastatic disease. In the present study, Brown Norway rats with syngeneic grafted colon carcinomas were administered the minimal effective therapeutic dose of 400 MBq/kg lutetium-177 ((177)Lu)-DOTA-BR96. After 2 weeks, half of the animals were given 15 mg/kg unlabeled mAb BR96 as consolidation therapy. Treatment response and toxicity were monitored 100 days after the treatment with unlabeled BR96. The treatment with unlabeled mAb after RIT resulted in a complete response (CR) in 19 of 19 animals, while RIT alone resulted in a CR in 17 of 19 animals. The additional treatment did not affect the number of animals with metastatic disease or the time to clinical symptoms of metastases. RIT resulted in reversible myelotoxicity. The unlabeled mAb BR96 did not cause any additional toxicity, making it possible to repeat the consolidation therapy
The importance of spring atmospheric conditions for predictions of the Arctic summer sea ice extent
Recent studies have shown that atmospheric processes in spring play an important role for the initiation of the summer ice melt and therefore may strongly influence the September sea ice concentration (SSIC). Here a simple statistical regression model based on only atmospheric spring parameters is applied in order to predict the SSIC over the major part of the Arctic Ocean. By using spring anomalies of downwelling longwave radiation or atmospheric water vapor as predictor variables, correlation coefficients between observed and predicted SSIC of up to 0.5 are found. These skills of seasonal SSIC predictions are similar to those obtained using more complex dynamical forecast systems, despite the fact that the simple model applied here takes neither information of the sea ice state, oceanic conditions nor feedback mechanisms during summer into account. The results indicate that a realistic representation of spring atmospheric conditions in the prediction system plays an important role for the predictive skills of a model system.Swedish Research Council FORMA
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