Abstract: A blue light emitting semiconductor nanocrystal having an quantum yield of greater than 20% can be incorporated in a light emitting device.

Abstract: A composition can include a complex, where the complex includes a photoluminescent nanostructure and a polymer free from selective binding to an analyte, the polymer adsorbed on the photoluminescent nanostructure, and a selective binding site associated with the complex.

Abstract: A power converter for converting DC power to DC power includes an inverter stage having two or more switched inverters configured to receive DC power from a source and produce a switched AC output power signal. A transformation stage is coupled to receive the switched output power signal from the inverter stage, shape the output power signal, and produce a shaped power signal. A rectifier stage having two or more switched inverters coupled to receive the shaped power signal and convert the shaped power signal to a DC output power signal is included. A controller circuit is coupled to operate the power converter in a variable frequency multiplier mode where at least one of the switched inverters is switched at a frequency or duty cycle that results in an output signal having a frequency that is a harmonic of the fundamental frequency being generated by the power converter.

Abstract: Articles and methods comprising persistent carbenes are provided, as well as related compositions. In some embodiments, a persistent carbene may be associated with a portion of a substrate (e.g., at least a portion of a surface on the substrate). In certain embodiments, the association of persistent carbene with the substrate may be used to affect certain properties of substrate (e.g., surface chemistry, stability). In some cases, a persistent carbene may be functionalized after association with a portion of a substrate. In some embodiments, a persistent carbene and at least one secondary compound may be associated with a portion of a substrate. Articles and methods of the present invention may be useful for applications involving electronics, sensing, microfabrication, nanotechnology, biomimetic, and drug delivery, amongst others.

Abstract: Articles and methods for stem cell differentiation are generally described. In some embodiments, an article for stem cell differentiation may comprise an oxygen permeable substrate having at least a portion of a surface coated with a matrix. The matrix may allow the surface chemistry of the substrate to be altered, such that the cell-substrate surface interactions may be finely controlled without substantially affecting the oxygen permeability of the substrate. The surface chemistry may be altered to promote directed stem cell differentiation by, e.g., modification of the matrix surface with a specific density of biological molecules. In some embodiments, methods for stem cell differentiation may comprise directing the differentiation of stem cells on the articles, described herein, under suitable environmental conditions.

Abstract: A power converter includes a PCB and a semiconductor die coupled to the PCB. The semiconductor die includes first through fourth switching devices. The power converter further includes a first energy storage element electrically connected to the first and second switching devices and a second energy storage element electrically connected to the third and fourth switching devices. The first energy storage element is mounted over the first and second switching devices and the second energy storage element is mounted over the third and fourth switching devices.

Abstract: A dodecamer peptide, and its modified variant, having a repeating glycine-lysine sequence was created and formed to bind with high affinity to oxide surfaces and certain activated polymeric surfaces. Reversible binding characteristics of the peptides were demonstrated. The peptides were integrated with proteins, cells and fusion proteins to provide attachment of the proteins, cells and fusion proteins to solid material structures. The peptides can be used to functionalize surfaces of components within mechanical, biomechanical, micro fluid, electronic, bio electronic, bio-optical, and biochemical devices. Experiments were canied out to assess functionalization and reusability of a suspended mass resonator's cantilever.

Abstract: A sensor can include a conductive region in electrical communication with at least two electrodes, the conductive region can include a composite of a polymer and SWCNTs immobilized onto a substrate. In certain embodiment, a linker can be grafted on the substrate. The linker can connect the substrate and the composite of the polymer and SWCNTs. In certain embodiments, the linker can covalently bond the polymer to the substrate. In certain embodiments, metal nanoparticles or ions can be incorporated as a metal sensitizer to confer further selectivity or sensitivity to the device. In certain embodiments, the polymer can act as a ligand for a variety of metal ions. By incorporating a specific metal ion, the sensor can selectively detect a specific analyte. In certain embodiments, the composite of the polymer and SWCNTs can be functionalized. In certain embodiments, the composite can further include a sensing element.

Abstract: A CNC machine shaping tool is efficiently used by monitoring human audible sound during shaping. A sound information set is created for a tool shaping a workpiece. Shaping sounds are recorded and sliced into short term units. A human operator assigns tool condition labels to each slice. Short term units are combined into mid term units. Noise is reduced by profiling. Mid term sound related features of time and frequency domains are extracted. Dimensionality is reduced by robust principal component analysis. The principal component set is balanced, e.g. by SMOTE. A classifier and principal components are selected. An information set of patterns of values of selected principal components for the tool is created. In an industrial setting, shaping sounds are recorded, noise reduced and select principal component vector values are compared to the tool condition labeled patterns of values in the information set to identify tool condition before deterioration.

Abstract: A device for collecting contaminants from water samples is provided. The device includes a solid sorbent that collects and stores the contaminants from water samples. The solid sorbent is configured to allow for the preservation of the stored contaminants. The concentrations of the contaminants in the water samples are determined via analysis of the solid sorbent or via elution of the stored contaminants from the sorbent and analysis of the eluate solution.

Abstract: Colloidal perovskite nanoplatelets can provide a material platform, with tunability extending from the deep UV, across the visible, into the near-IR. The high degree of spectral tunability can be achieved through variation of the cation, metal, and halide composition as well as nanoplatelet thickness.

Abstract: A method for synthesizing nanoparticles by sonofragmentation includes dispersing ultra-thin substrate units in a solvent chosen for suitability for sonofragmentation of the substrate, forming a suspension; ultrasonicating the suspension for a length of time sufficient to fragment the substrate into nanoparticles that are dispersed in the solvent; and evaporating the solvent. Solvent exchange with a second solvent may be performed. The synthesized nanoparticles are highly crystalline and monodispersed. The surface of the synthesized nanoparticles may be functionalized by choosing the solvents according to chemistry related to the intended surface functionalization of the synthesized nanoparticles, by adding surfactants to one or more of the solvents, and/or by performing ligand exchange or chemical modification to replace surface-bonded solvent or surfactant molecules with other functional groups to produce nanoparticles having the desired surface functionalization.

Abstract: Communication bottlenecks, particularly in the downlink direction, are a common problem for many CubeSat developers. As described herein, a CubeSat module for a CubeSat comprises an optical transmitter to transmit data to a remote terminal, a receiver to acquire an optical beacon from a remote terminal, and a fine-pointing module operably and directly coupleable to a coarse-pointing module of the CubeSat. The fine-pointing module is configured to point the optical transmitter toward the remote terminal with an accuracy range that overlaps with an accuracy range of the coarse-pointing module of the CubeSat so as to establish a communications link between the CubeSat and the remote terminal over a low-Earth-orbit (LEO) distance.

Abstract: A multi-layer semiconductor device includes a first semiconductor structure having first and second opposing surfaces, the second surface of the first semiconductor structure having at least a first semiconductor package pitch. The multi-layer semiconductor device also includes a second semiconductor structure having first and second opposing surfaces, the first surface of the second semiconductor structure having a second semiconductor package pitch. The multi-layer semiconductor device additionally includes a third semiconductor structure having first and second opposing surfaces, the first surface of the third semiconductor structure having a third semiconductor package pitch which is different from at least the second semiconductor package pitch. The second and third semiconductor structures are provided on a same package level of the multi-layer semiconductor device. A corresponding method for fabricating a multi-layer semiconductor device is also provided.

Abstract: Described herein are redox flow batteries comprising a first aqueous electrolyte comprising a first type of redox active material and a second aqueous electrolyte comprising a second type of redox active material. The first type of redox active material may comprise one or more types of quinoxalines, or salts thereof. Methods for storing and releasing energy utilizing the described redox flow batteries are also provided.

Abstract: A set of machines and related systems build structures by the additive assembly of discrete parts. These digital material assemblies constrain the constituent parts to a discrete set of possible positions and orientations. In doing so, the structures exhibit many of the properties inherent in digital communication such as error correction, fault tolerance and allow the assembly of precise structures with comparatively imprecise tools. Assembly of discrete cellular lattices by a Modular Isotropic Lattice Extruder System (MILES) is implemented by pulling strings of lattice elements through a forming die that enforces geometry constraints that lock the elements into a rigid structure that can then be pushed against and extruded out of the die as an assembled, loadbearing structure.

Abstract: A radiation detection technique employs field enhancing structures and electroluminescent materials to converts incident Terahertz (THz) radiation into visible light and/or infrared light. In this technique, the field-enhancing structures, such as split ring resonators or micro-slits, enhances the electric field of incoming THz light within a local area, where the electroluminescent material is applied. The enhanced electric field then induces the electroluminescent material to emit visible and/or infrared light via electroluminescent process. A detector such as avalanche photodiode can detect and measure the emitted light. This technique allows cost-effective detection of THz radiation at room temperatures.

Abstract: In one embodiment, a method of amplifying temporal variation in at least two images comprises examining pixel values of the at least two images. The temporal variation of the pixel values between the at least two images can be below a particular threshold. The method can further include applying signal processing to the pixel values.

Abstract: An optoelectronic device as well as its methods of use and manufacture are disclosed. In one embodiment, an optoelectronic device includes first and second semiconducting atomically thin layers with corresponding first and second lattice directions. The first and second semiconducting atomically thin layers are located proximate to each other, and an angular difference between the first lattice direction and the second lattice direction is between about 0.000001° and 0.5°, or about 0.000001° and 0.5° deviant from of a Vicnal angle of the first and second semiconducting atomically thin layers. Alternatively, or in addition to the above, the first and second semiconducting atomically thin layers may form a Moiré superlattice of exciton funnels with a period between about 50 nm to 3 cm. The optoelectronic device may also include charge carrier conductors in electrical communication with the semiconducting atomically thin layers to either inject or extract charge carriers.

Abstract: Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency or the engine.