Abstract: A waveguide and a communication system including the waveguide are described. The waveguide is configured to propagate an electromagnetic wave having an operating frequency along the waveguide. The waveguide includes a substrate having a first dielectric constant, and an array of spaced apart unit cells at least partially embedded in the substrate and arranged along the waveguide. Each of a plurality of the unit cells in the array of spaced apart unit cells has a first transmission parameter S121 having a lowest resonant frequency ?1 and includes a dielectric body and one or more electrically conductive layers disposed on and partially covering the dielectric body. The dielectric body has a second dielectric constant greater than the first dielectric constant at the operating frequency and has a second transmission parameter S221 having a lowest resonant frequency ?2 greater than ?1.

Abstract: Electromagnetic interference (EMI) shielding articles and methods of producing and using the same are described. The articles include electrically conductive fillers and silsesquioxane-like (SSQ-like) particles distributed inside a polymeric matrix material. In some cases, adding the SSQ-like particles leads to increased porosity of the articles which improves EMI absorbing performance.

Abstract: A waveguide and a communication system including the waveguide are described. The waveguide is configured to propagate an electromagnetic wave having an operating frequency along the waveguide. The waveguide includes a substrate having a first dielectric constant, and an array of spaced apart unit cells at least partially embedded in the substrate and arranged along the waveguide. Each of a plurality of the unit cells in the array of spaced apart unit cells has a first transmission parameter S121 having a lowest resonant frequency ?1 and includes a dielectric body and one or more electrically conductive layers disposed on and partially covering the dielectric body. The dielectric body has a second dielectric constant greater than the first dielectric constant at the operating frequency and has a second transmission parameter S221 having a lowest resonant frequency ?2 greater than ?1.

Abstract: A vehicle control system and method includes identifying a segment of a route where one or more first vehicle systems were operated manually instead of operated by one or more processors according to one or more trip plans during prior traversals of the segment by the one or more first vehicle systems. A segment plan is generated for traversing the segment under control of the one or more processors. The segment plan is generated based on how the one or more first vehicle systems were manually operated during the prior traversals of the segment. One or more second vehicle systems are controlled with the one or more processors to traverse the segment according to the segment plan.

Abstract: Methods and systems for determining a tumor volume from image data obtained from a functional scanner. The methods and systems can include identifying a portion within a region of interest corresponding to a liver that varies in intensity with its corresponding neighboring portion by a threshold. The method and systems can further include determining a volume of the portion without identifying a boundary of the portion. The portion can also be tracked over time. The image data can include a scan from a SPECT scanner.

Abstract: Conductive particles, articles including such particles, and methods of making such conductive particles, are provided; wherein the conductive particles include: a core particle including at least one of a glass, a glass-ceramic, or a metal; surface particles adhered to the core particle; and a metal coating disposed on at least a portion of the core and surface particles; wherein the core particle is larger than the surface particles.

Abstract: Electric field grading compositions comprise a particulate cupric oxide dispersed in a matrix material, wherein the electric field grading composition has a threshold voltage, a breakdown voltage, and exhibits a reversible electric field switchable current-voltage relationship that substantially follows the equation: I=kV? wherein: I is current in amperes; k is a constant greater than 0; V is applied voltage in volts, wherein V is between the threshold voltage and the breakdown voltage, inclusive; and ? is a real number greater than 1. The electric field grading composition is useful for reducing electric field stress at a joint or termination of a conductive substrate. Articles including the electric field grading disposed on a surface of a conductive substrate are also disclosed.

Abstract: Compositions (120), which may be in the form of flexible films, molded bodies, or printable inks, can incorporate ceramic particles (122) comprising titanium monoxide (TiO) for purposes of electromagnetic interference (EMI) shielding at megahertz through gigahertz frequencies. One or more additional ceramic particles can also be included. The compositions comprise a composite material (120) which includes the ceramic particles (122) dispersed within a matrix material (121), such as a polymer. Methods associated with such compositions are also described.

Abstract: Radar standing wave dampening systems and components are described. In particular, systems and components including an absorber composite including at least one of ceramic filler, magnetic filler, or conductive filler materials are described. Such components can reduce the intensity of standing waves and may also be combined in systems with one or more gradient permittivity tapes or films.

Abstract: Gradient permittivity films are described. In particular, gradient permittivity films that include a first continuous matrix of a first component having a first relative permittivity and a second component disposed within the continuous matrix having a second relative permittivity. The first permittivity is greater than the second permittivity for at least one wavelength between 20 GHz and 300 GHz. Such films may be useful in improving the signal to noise ratio for transmitting and receiving units behind a protective cover.

Abstract: Gradient permittivity films are described. In particular, gradient permittivity films including a plurality of layers each having a thickness where at least one layer is perforated and has a different air volume fraction from another of the plurality of layers by at least 0.05. Such films may be useful in improving the signal to noise ratio for transmitting and receiving units operating between 20 GHz and 300 GHz behind a protective cover.

Abstract: Electrically conductive articles are provided, including a composite including (a) a resin, and (b) electrically conductive shaped particles distributed in the resin, the particles having a monosized distribution. Each particle has a shape including at least a first surface and a second surface intersecting the first surface at an angle a between about 5 degrees and about 150 degrees. The composite has a thickness and often each of the electrically conductive shaped particles distributed in the resin is oriented within the resin such that the particle does not extend beyond the thickness of the composite. A method for making an electrically conductive article is also provided, including (a) providing electrically conductive shaped particles having a monosized distribution, and (b) distributing the particles into a resin to form a composite.

Abstract: At least some aspects of the present disclosure feature a waveguide for propagating an electromagnetic wave. The waveguide includes a base material and a plurality of resonators disposed in a pattern, the plurality of resonators having a resonance frequency. Each of the plurality of resonators has a relative permittivity greater than a relative permittivity of the base material. At least two of the plurality of resonators are spaced according to a lattice constant that defines a distance between a center of a first one of the resonators and a center of a neighboring second one of the resonators.

Abstract: The invention relates to a material, process and method for the selective analysis of small molecules. Particularly the invention provides a material and a technique for the analysis of small molecules excluding other large molecular weight (MW) analytes. The process involves selective detection of low molecular weight molecules from a sample comprising the steps of placing said sample with SBA-15 particles; and subjecting the same to desorption ionization mass spectrometry, wherein low molecular weight molecules are selectively detected over the higher molecular weight molecules. A kit for the selective analysis of small molecules is also provided.

Abstract: Electromagnetic interference (EMI) shielding composites and methods of making and using the same are described. The composites include high-loading-level ceramic particles distributed in a low-dielectric-loss matrix material having a dielectric loss tangent in the range of about 0.0001 to about 0.005. In one case, the composite includes CuO particles distributed in silicone. The composites exhibit dielectric absorber properties in the high frequency range.

Abstract: Nonlinear composite compositions comprise a dielectric matrix material and flakes of a mixed metal oxide having the formula M1xM2yOz dispersed in the dielectric matrix material. M1 is selected from the group consisting of alkali metals, alkaline earth metals, and combinations thereof. M2 is a transition metal or post-transition metal, wherein M2 has an atomic number no greater than 78. The number x is in the range 0.3?x?1, y is a number in the range 0.5?y?1.5, and z is a number selected such that the mixed metal oxide is electrically neutral, wherein the amount of flakes in the nonlinear composite composition is sufficient that the nonlinear composite composition has a nonlinear increasing conductivity in response to increasing electric field. Methods of making nonlinear composite compositions and articles including them are disclosed.

Abstract: An electronic article comprises an electronic component bonded to a composite composition. The composite composition comprises a crosslinked silicone foam having polydimethylsiloxane segments, and electromagnetically responsive particles retained in the crosslinked silicone foam. Composite compositions comprising carbon nanotubes and electromagnetic wave shielding articles including them are also disclosed.

Abstract: Conductive particles, articles including such particles, and methods of making such conductive particles, are provided; wherein the conductive particles include: a core particle including at least one of a glass, a glass-ceramic, or a metal; surface particles adhered to the core particle; and a metal coating disposed on at least a portion of the core and surface particles; wherein the core particle is larger than the surface particles.

Abstract: Polymer composites that are suitable for use as electromagnetic interference mitigaters include a lossy polymeric matrix, ceramic particles dispersed within the polymeric matrix, and conductive particles dispersed within the polymeric matrix. The lossy polymeric matrix may be a fluorocarbon-based polymer matrix, or an epoxy-based polymer matrix. The ceramic particles may be metal oxide particles, especially copper oxide (CuO) particles. The conductive particles may be carbon black. Other electromagnetic interference mitigating polymer matrices include a lossy polymeric matrix and copper oxide (CuO) particles dispersed within the polymeric matrix.

Abstract: At least some aspects of the present disclosure feature a communication device for propagating an electromagnetic wave around a blocking structure. The communication device includes a passive coupling device to capture the electromagnetic wave, and a waveguide electromagnetically coupled to the coupling device. The waveguide is disposed around the blocking structure. The waveguide has a resonance frequency matched with the coupling device. The waveguide is configured to propagate the electromagnetic wave captured by the coupling device.