Student ultrasound education - current views and controversies.

As an extension of the clinical examination and as a diagnostic and problem-solving tool, ultrasound has become an established technique for clinicians. A prerequisite for high-quality clinical ultrasound practice is adequate student ultrasound training. In light of the considerable heterogeneity of ultrasound curricula in medical studies worldwide, this review presents basic principles of modern medical student ultrasound education and advocates for the establishment of an ultrasound core curriculum embedded both horizontally and vertically in medical studies.

Towards Two-Photon Polymerization-Compatible Diffractive Optics for Micro-Mechanical Applications.

Diffractive optics are structured optical surfaces that manipulate light based on the principles of interference and diffraction. By carefully designing the diffractive optical elements, the amplitude, phase, direction, and polarization of the transmitted and reflected light can be controlled. It is well-known that the propagation of light through diffractive optics is sensitive to changes in their structural parameters.

Mechanical Control of the Optical Bandgap in One-Dimensional Photonic Crystals.

Over the last several years, two-photon polymerization has been a popular fabrication approach for photonic crystals due to its high spatial resolution. One-dimensional photonic crystals with photonic bandgap reflectivities over 90% have been demonstrated for the infrared spectral range. With the success of these structures, methods which can provide tunability of the photonic bandgap are being explored.

Terahertz anisotropic response of additively manufactured one-dimensional photonic crystals.

A polymer-based, one-dimensional photonic crystal exhibiting anisotropic responses was demonstrated in the terahertz frequency range. The photonic crystal was composed of alternating compact and low-density polymethacrylate layers. The low-density layers consisted of sub-wavelength sized columns, which were slanted 45° with respect to the substrate surface normal to achieve form-birefringence.

Tunable cavity-enhanced terahertz frequency-domain optical Hall effect.

Presented here is the development and demonstration of a tunable cavity-enhanced terahertz (THz) frequency-domain optical Hall effect (OHE) technique. The cavity consists of at least one fixed and one tunable Fabry-Pérot resonator. The approach is suitable for the enhancement of the optical signatures produced by the OHE in semi-transparent conductive layer structures with plane parallel interfaces.

Si(bzimpy) - a hexacoordinate silicon pincer complex for electron transport and electroluminescence.

A neutral hexacoordinate silicon complex containing two 2,6-bis(benzimidazol-2'-yl)pyridine (bzimpy) ligands has been synthesized and explored as a potential electron transport layer and electroluminescent layer in organic electronic devices. The air and water stable complex is fluorescent in solution with a λmax = 510 nm and a QY = 57%. Thin films grown via thermal evaporation also fluoresce and possess an average electron mobility of 6.

Nanomaterials as stationary phases and supports in liquid chromatography.

The development of various nanomaterials over the last few decades has led to many applications for these materials in liquid chromatography (LC). This review will look at the types of nanomaterials that have been incorporated into LC systems and the applications that have been explored for such systems. A number of carbon-based nanomaterials and inorganic nanomaterials have been considered for use in LC, ranging from carbon nanotubes, fullerenes and nanodiamonds to metal nanoparticles and nanostructures based on silica, alumina, zirconia and titanium dioxide.

In-situ terahertz optical Hall effect measurements of ambient effects on free charge carrier properties of epitaxial graphene.

Unraveling the doping-related charge carrier scattering mechanisms in two-dimensional materials such as graphene is vital for limiting parasitic electrical conductivity losses in future electronic applications. While electric field doping is well understood, assessment of mobility and density as a function of chemical doping remained a challenge thus far. In this work, we investigate the effects of cyclically exposing epitaxial graphene to controlled inert gases and ambient humidity conditions, while measuring the Lorentz force-induced birefringence in graphene at Terahertz frequencies in magnetic fields.

Optical Hall effect-model description: tutorial.

The optical Hall effect is a physical phenomenon that describes the occurrence of magnetic-field-induced dielectric displacement at optical wavelengths, transverse and longitudinal to the incident electric field, and analogous to the static electrical Hall effect. The electrical Hall effect and certain cases of the optical Hall effect observations can be explained by extensions of the classic Drude model for the transport of electrons in metals. The optical Hall effect is most useful for characterization of electrical properties in semiconductors.

Transient Absorption Measurements on Anisotropic Monolayer ReS2.

Anisotropic optical and transport properties of monolayer ReS2 fabricated by mechanical exfoliation are reported. Transient absorption measurements with different polarization configurations and sample orientations reveal that the absorption coefficient and transient absorption are both anisotropic, with maximal and minimal values occurring when the light polarization is parallel and perpendicular to the Re atomic chains, respectively. The maximal values are about a factor of 2.

The retention of liquid by columnar nanostructured surfaces during quartz crystal microbalance measurements and the effects of adsorption thereon.

Hypothesis: A surface comprising spatially coherent columnar nanostructures is expected to retain intercolumnar liquid during a quartz crystal microbalance measurement due to the surface structure. Part of the liquid retained by the nanostructures may then be displaced by adsorbate.

Experiments: Slanted columnar nanostructure thin films were designed to vary in height but remain structurally similar, fabricated by glancing angle deposition, and characterized by generalized ellipsometry.

Multilayer graphitic coatings for thermal stabilization of metallic nanostructures.

We demonstrate that graphitic coatings, which consist of multilayer disordered graphene sheets, can be used for the thermal protection of delicate metal nanostructures. We studied cobalt slanted nanopillars grown by glancing angle deposition that were shown to melt at temperatures much lower than the melting point of bulk cobalt. After graphitic coatings were conformally grown over the surfaces of Co nanopillars by chemical vapor deposition, the resulting carbon-coated Co nanostructures retained their morphology at elevated temperatures, which would damage the uncoated structures.

Protein adsorption on and swelling of polyelectrolyte brushes: A simultaneous ellipsometry-quartz crystal microbalance study.

With a coupled spectroscopic ellipsometry-quartz crystal microbalance with dissipation (QCM-D) experimental setup, quantitative information can be obtained about the amount of buffer components (water molecules and ions) coupled to a poly(acrylic acid) (PAA) brush surface in swelling and protein adsorption processes. PAA Guiselin brushes with more than one anchoring point per single polymer chain were prepared. For the swollen brushes a high amount of buffer was found to be coupled to the brush-solution interface in addition to the content of buffer inside the brush layer.

Generalized far-infrared magneto-optic ellipsometry for semiconductor layer structures: determination of free-carrier effective-mass, mobility, and concentration parameters in n-type GaAs.

We report for the first time on the application of generalized ellipsometry at far-infrared wavelengths (wave numbers from 150 cm(-1) to 600 cm(-1)) for measurement of the anisotropic dielectric response of doped polar semiconductors in layered structures within an external magnetic field. Upon determination of normalized Mueller matrix elements and subsequent derivation of the normalized complex Jones reflection matrix r of an n-type doped GaAs substrate covered by a highly resistive GaAs layer, the spectral dependence of the room-temperature magneto-optic dielectric function tensor of n-type GaAs with free-electron concentration of 1.6 x 10(18) cm(-3) at the magnetic field strength of 2.