Characterization of Electric Fields Generated by Electricidal Coatings for Biofilm-Resistant Catheters

Catheter associated urinary tract infections (CAUTIs) are an endemic problem in the American medical system, causing nearly 32% of all hospital-acquired infections (HAIs) [1]. Novel antimicrobial coatings for catheters, consisting of metal powders (Ag/Ag2O) and polydimethylsiloxane (PDMS), have recently been developed to combat this problem [2,3]. The active ingredients in these coatings were modeled using simplified assumptions in both ANSYS Maxwell and Quantum Espresso to determine the electric field strength at various particle radii. SEM/EDX analysis of the Ag/Ag2O coating was also performed to simulate the particles in ANSYS and provide comparison between idealized models and actual particle geometries.

Track Finding

There is no systematic theory of track finding yet. Therefore, the first section of this chapter presents a list of basic techniques which have been successfully used, stand-alone or in combination, in past and present experiments. Among them are the conformal transformation, the Hough and the Legendre transform, cellular automata and neural networks, pattern matching, and track following by the combinatorial Kalman filter. The following section gives a brief excursion into online or real-time track finding in the collider experiments CDF, ATLAS, and CMS. As track finding in most cases delivers some candidates that do not correspond to actual particle tracks, the concluding section discusses methods for an efficient selection of valid candidates.

Experimental and Numerical Investigation on the Transport Characteristics of Particle-Fluid Mixture in Y-Shaped Elbow

The Y-shaped elbow is used as a connecting pipe between the buffer and the lift pipe in the deep-sea mining system. After being mixed with seawater in the Y-shaped elbow, nodule particles are lifted to the sea surface mining ship via the lift pump. In this paper, we employ a computational fluid dynamics and discrete element coupled method (CFD-DEM) to study the characteristics of particle transport in the Y-shaped elbow. Considering a large diameter of the particles, we discuss the behavior of particles and fluid under different conveying velocities. In addition, the simulation was verified based on the experiment. The results show that the simulation agrees well with the experiment. On this basis, the distribution and motion characteristics of the particles in the Y-shaped elbow were obtained. The interaction between fluid and particles is also discussed. These findings suggest that the particles can be successfully transported when the pump runs at medium to high frequencies. The particles are basically moving along the pipe wall and slower than the fluid flow. Moreover, it was found that the particle motions are more complex with the increasing of conveying velocities, and it is closely related to the secondary flow of fluid. Some suggestions on the actual particle transportation can be put forward based on the research in this paper.

Particle Identification Using Light Scattering

We discuss some experience of solving an inverse light scattering problem for single, spherical, homogeneous particles using least squares global optimization. If there is significant noise in the data, the particle corresponding to the “best” solution may not correspond well to the “actual” particle. One way of overcoming this difficulty involves the use of peak positions in the experimental data as a means of distinguishing genuine from spurious solutions. We introduce two composite approaches which combine conventional data fitting with peak-matching and show that they lead to a more robust identification procedure.

On the motion of charged particles in a sheared force-free magnetic field

This paper considers single-particle trajectories in a planar sheared force-free magnetic field. A specific feature of this magnetic configuration is the absence of both gradient and curvature magnetic drifts, as well as a diamagnetic force along field lines. Therefore, in the framework of the drift approximation, the motion of the particle guiding centre does not feel the magnetic field's non-uniformity. Here we discuss how the latter affects actual particle trajectories, making them quite different from simple circular gyromotion even when the Larmor radius is small. It is also shown how magnetic confinement ceases to work when the Larmor radius becomes comparable to the spatial scale of the field variation.

Light scattering size estimation of nearly monodisperse spherical particles in the multivalued region: A reminiscence

For the size estimation of large, nearly monodisperse spherical particles, the forward angle dissymmetry technique (FAD) has been used and the results compared with data obtained by the transmission electron microscopy (TEM) and integral turbidity ratio (ITR) methods. Starting with a certain relative particle size which depends on the chosen angle pair, the FAD functions go through several extremes and become multivalued. The possibility of the particle size estimation under such conditions and, also, without the knowledge of actual particle concentration (but knowing the relative refractive index), is discussed in this paper.

Diffusion of resonance particles in strong plasma turbulence

This paper derives an expression for the velocity space diffusion tensor (time asymptotic) for resonant particles in the weak-coupling limit of strong plasma turbulence theory. The analysis is based on an improved approximation scheme for the determination of the actual particle trajectories, rather than the determination of &ensemble averaged particle orbits’ with the help of the &average Vlasov propagator’. Except for numerical factors of order unity, the results agree with those of Birmingham & Bornatici, both when Tc → 0 (Tc is the correlation width of the fluctuating field as seen by the resonant particles), and when Tc is finite but small. The paper indicates the limits of this method, as well as those of Birmingham & Bornatici.

The Physico-Chemical Properties of Latex and Their Significance in Manufacture

The first physico-chemical property of latex to be discussed is that of viscosity, if latex can be said to have a viscosity. As will be seen later, this property is so important in many manufacturing processes, such as extrusion, dipping, and centrifuging that the fundamentals must be understood. Latex, as is well known, is a suspension of irregularly shaped particles, many pear-shaped, in an aqueous medium which itself contains an appreciable proportion of other dissolved and suspended matter. These particles, according to present ideas, are surrounded by a strong adsorption layer, which influences very considerably the properties of the latex. As a result of its composite structure, latex and more particularly latex compounds have rather interesting properties. From the point of view that latex creams under gravity, that the particle carries an appreciable electric charge, and depends partly on this for its stability, and that the swelling of the actual particle in water is very small, it may be called hydrophobic. On the other hand, in view of its behavior with respect to dehydrating agents, the manner in which it forms aqueous voluminous gels, and more particularly in its reaction to shearing forces, latex may be classed as hydrophilic. Its hydrophilic character is conditioned by the material adsorbed on the surface of the particles and is more pronounced in compounded and treated latices.