Apparatus for recovering matter adhered to a host surface

The development of an apparatus for removing and recovering matter adhered to a host surface is described. The device consists of a pickup head with an ultrasonic transducer adapted to deliver ultrasonic pressure waves against the material. The ultrasonic waves agitate the material and cause its separation from the surface. A vacuum system recovers the material and delivers it to suitable storage containers

Development of a sensitive superconducting gravity gradiometer for geological and navigational applications

A sensitive and stable gravity gradiometer would provide high resolution gravity measurements from space. The instrument could also provide precision tests of fundamental laws of physics and be applied to inertial guidance systems of the future. This report describes research on the superconducting gravity gradiometer program at the University of Maryland from July 1980 to July 1985. The report describes the theoretical and experimental work on a prototype superconducting gravity gradiometer. The design of an advanced three-axis superconducting gravity gradiometer is also discussed

Analysis on the hull girder ultimate strength of a bulk carrier using simplified method based on an incremental-iterative approach

The hull girder ultimate strength of a typical bulk carrier is analyzed using a simplified method based on an incremental-iterative approach. First, vertical bending moment is examined by seven different methods. The moment versus curvature curves and the values of the ultimate longitudinal moments at collapse states are determined for both hogging and sagging cases. Second, the ultimate strength under coupled vertical and horizontal bending moment is accounted. An interaction curve is obtained, which corresponds to the results of series of calculation for the ship hull subject to bending conditions with different angles of curvature. It is found that the interaction curve is asymmetrical because the hull cross section is not symmetrical with respect to the horizontal axis and the structural response of the elements under compression is different from that under tension due to nonlinearity caused by buckling. The angles of the resultant bending moment vector and that of the curvature vector are different in investigated cases. The interaction design equations proposed by other researches are also addressed to discuss the results presented by this study

Photon Shot Noise Dephasing in the Strong-Dispersive Limit of Circuit QED

We study the photon shot noise dephasing of a superconducting transmon qubit in the strong-dispersive limit, due to the coupling of the qubit to its readout cavity. As each random arrival or departure of a photon is expected to completely dephase the qubit, we can control the rate at which the qubit experiences dephasing events by varying \textit{in situ} the cavity mode population and decay rate. This allows us to verify a pure dephasing mechanism that matches theoretical predictions, and in fact explains the increased dephasing seen in recent transmon experiments as a function of cryostat temperature. We investigate photon dynamics in this limit and observe large increases in coherence times as the cavity is decoupled from the environment. Our experiments suggest that the intrinsic coherence of small Josephson junctions, when corrected with a single Hahn echo, is greater than several hundred microseconds.Comment: 5 pages, 4 figures; includes Supporting Online Material of 6 pages with 5 figure

Two-phase stretching of molecular chains

While stretching of most polymer chains leads to rather featureless force-extension diagrams, some, notably DNA, exhibit non-trivial behavior with a distinct plateau region. Here we propose a unified theory that connects force-extension characteristics of the polymer chain with the convexity properties of the extension energy profile of its individual monomer subunits. Namely, if the effective monomer deformation energy as a function of its extension has a non-convex (concave up) region, the stretched polymer chain separates into two phases: the weakly and strongly stretched monomers. Simplified planar and 3D polymer models are used to illustrate the basic principles of the proposed model. Specifically, we show rigorously that when the secondary structure of a polymer is mostly due to weak non-covalent interactions, the stretching is two-phase, and the force-stretching diagram has the characteristic plateau. We then use realistic coarse-grained models to confirm the main findings and make direct connection to the microscopic structure of the monomers. We demostrate in detail how the two-phase scenario is realized in the \alpha-helix, and in DNA double helix. The predicted plateau parameters are consistent with single molecules experiments. Detailed analysis of DNA stretching demonstrates that breaking of Watson-Crick bonds is not necessary for the existence of the plateau, although some of the bonds do break as the double-helix extends at room temperature. The main strengths of the proposed theory are its generality and direct microscopic connection.Comment: 16 pges, 22 figure