Abstract: A structural assembly may include a first prefabricated structural element having a first angled face at an end of the first prefabricated structural element; a second prefabricated structural element having a second angled face at an end of the second prefabricated structural element, the end of the second precast barrier segment connected to the end of the first prefabricated structural element; and a coupling assembly connecting the first angled face of the first prefabricated structural element to the second angled face of the second prefabricated structural element. The coupling assembly provides shear and moment continuity across the first and second prefabricated structural elements. This allows for a variable gap due to manufacturing tolerances, construction tolerances, and/or expansion or contraction.

Abstract: An unmanned aerial vehicle (UAV) can be configured for crop height estimation. In some examples, the UAV includes an aerial propulsion system, a laser scanner configured to face downwards while the UAV is in flight, and a control system. The laser scanner is configured to scan through a two-dimensional scan angle and is characterized by a maximum range. The control system causes the UAV to fly over an agricultural field and maintain, using the aerial propulsion system and the laser scanner, a distance between the UAV and a top of crops in the agricultural field to within a programmed range of distances based on the maximum range of the laser scanner. The control system determines, using range data from the laser scanner, a crop height from the top of the crops to the ground.

Abstract: A method of fabricating a continuous nanofiber is described. The method includes preparing a solution of one or more polymers and one or more solvents and electrospinning the solution by discharging the solution through one or more liquid jets into an electric field to yield one or more continuous nanofibers. The electrospinning process (i) highly orients one or more polymer chains in the one or more continuous nanofibers along a fiber axis of the one or more continuous nanofibers, and (ii) suppresses polymer crystallization in the one or more continuous nanofibers. The one or more continuous nanofibers can have diameters below about 250 nanometers and exhibit an increase in fiber strength and modulus while maintaining strain at failure, resulting in an increase in fiber toughness.

Abstract: Methods and systems for synthesizing heparin compounds are provided. The chemoenzymatic synthesis of structurally homogeneous low molecular weight heparins that have a reversible anticoagulant activity is provided. Also disclosed are heparin compounds having anticoagulant activity, including a binding affinity to antithrombin and an anti-Xa activity, but no detectable anti-lla activity. Additionally, provided are synthetic, low-molecular weight heparin compounds with reversible anticoagulant activity, where the anticoagulant activity is reversible by protamine.

Abstract: In one implementation, a direct-push oxidant candle apparatus for the treatment of contaminated groundwater through direct-push installation methods includes: a drive tip positioned at a bottom end of the apparatus, the drive tip having one or more front surfaces that are shaped to create a bore as force is applied to an opposite base surface of the drive tip; a structural pathway that is connected to and extend upwardly from the base surface of the drive tip; one or more oxidant delivery devices that are enclosed within the structural pathway; and one or more fluid supply lines that extend from one or more locations outside of the bore and that terminate at or near a bottom end of the structural pathway so that fluid supplied through the fluid supply lines travels through the structural pathway and along the one or more oxidant delivery devices.

Abstract: This disclosure features an apparatus including a motor controller to generate control signals to control an electric motor. The motor controller includes a first saturation controller to generate a first saturation controller output based on feedback signals associated with the electric motor. The motor controller further includes a duty ratio modulator coupled to the first saturation controller. The duty ratio modulator is configured to determine activation times for a set of voltage vectors based on the first saturation controller output. The motor controller is configured to generate, at each switching cycle, a control signal based on the set of voltage vectors and the activation times for the set of voltage vectors, and provide the control signal for controlling the electric motor.

Abstract: Cross-linked amphiphile constructs that form self-assembled monolayers (SAMs) on metal surfaces such as gold surfaces are disclosed. These new SAMs generate well packed and highly oriented monolayer films on gold surfaces. A method for using the SAMs in the fabrication of biomolecule sensors is also disclosed.

Abstract: Systems and methods for perovskite single crystal growth include using a low temperature solution process that employs a temperature gradient in a perovskite solution in a container, also including at least one small perovskite single crystal, and a substrate in the solution upon which substrate a perovskite crystal nucleates and grows, in part due to the temperature gradient in the solution and in part due to a temperature gradient in the substrate. For example, a top portion of the substrate external to the solution may be cooled.

Abstract: A field effect transistor photodetector that can operate in room temperature includes a source electrode, a drain electrode, a channel to allow an electric current to flow between the drain and source electrodes, and a gate electrode to receive a bias voltage for controlling the current in the channel. The photodetector includes a light-absorbing material that absorbs light and traps electric charges. The light-absorbing material is configured to generate one or more charges upon absorbing light having a wavelength within a specified range and to hold the one or more charges. The one or more charges held in the light-absorbing material reduces the current flowing through the channel.

Abstract: A sensor having a substrate is provided in which structures are disposed on a surface of the substrate. The structures can be, e.g., nanostructures. Polarized light is directed toward the sensor, and birefringence of the structures with respect to the light is measured. Target particles that interact with the structures are detected based on changes in the measured birefringence.

Abstract: Cerium oxide nanorods having a variety of aspect ratios can be produced by providing a first mixture that includes a cerium precursor material, and using microwave to heat the first mixture to a first temperature for a period of time to produce first plurality of cerium oxide nanorods having a first range of aspect ratios. A second mixture that includes a cerium precursor material heated using microwave to a second temperature for a period of time to produce second plurality of cerium oxide nanorods having a second range of aspect ratios. The first plurality of cerium oxide nanorods and the second plurality of cerium oxide nanorods are mixed to produce third plurality of cerium oxide nanorods having the third range of aspect ratios that is broader than the first range or the second range.

Abstract: A grasper can include a first pantograph cell and a second pantograph cell coupled with the first pantograph cell. The first and second pantograph cells can be coupled together at a first pivot and a second pivot. The grasper can also include a finger extendable in a direction extending between the first pivot and the second pivot. The grasper can include a support base, where one or more links of the first pantograph cell can be slidably coupled with the support base for extending the grasper. In some embodiments, the grasper can be configured to extend along a curved path. In some embodiments, the finger can be biased in a direction away from an object to be grasped by the grasper, and also biased in a direction toward an object to be grasped by the grasper when the grasper is extended.

Abstract: A first system includes a feedstock load port and a feedstock discharge port. The first system also includes a tank configured to retain biomass feedstock for aerobic biodegradation. The first system further includes a mechanical ventilator in fluid communication with the tank. The mechanical ventilator is configured to supply air to facilitate the aerobic biodegradation of the biomass feedstock. The first system also includes an exhaust port configured to receive gas generated during the aerobic biodegradation. A second system includes a feedstock load port and a feedstock discharge port. The second system also includes a pressure vessel configured to retain biomass feedstock for anaerobic biodegradation. The second system further includes a gas release device to facilitate migration of gas within the pressure vessel. The second system also includes a water cycler configured to cycle water within the pressure vessel. The second system further includes an exhaust port.

Abstract: The present invention provides methods for obtaining plants that exhibit useful traits by transient suppression of the MSH1 gene of the plants. Methods for identifying genetic loci that provide for useful traits in plants and plants produced with those loci are also provided. In addition, plants that exhibit the useful traits, parts of the plants including seeds, and products of the plants are provided as well as methods of using the plants.

Abstract: A photodetector includes an anode that is transparent or partially transparent to light, a cathode and an active layer disposed between the anode and the cathode. The active layer includes a nanocomposite material that has a polymer blended with nanoparticles or organic electron trapping particles. The photodetector has a low dark current when not illuminated by light and has a high conductivity when illuminated by light, in which the light passes the anode and is absorbed by the active layer.

Abstract: A system includes a vessel configured to couple with a gas source for drawing gas into the vessel. The vessel is also configured to receive liquid. The system includes an overflow port in fluid communication with the environment external to the vessel. The overflow port is configured to separate gas within the vessel from the external environment. The system also includes an overflow conduit having an end within the overflow port so that when gas pressure within the vessel increases, liquid is received by the overflow conduit. Another system includes a tank defining an air space for receiving gas generated during the biodegradation of biomass feedstock. The second system also includes an exhaust port, a first evaporator, a first condenser, an expansion valve, and a compressor. The second system also includes a heat exchanger, a second evaporator, and a second condenser.

Abstract: Conductive concrete mixtures are described that are configured to provide EMP shielding and reflect and/or absorb, for instance, EM waves propagating through the conductive concrete mixture. The conductive concrete mixtures include cement, water, conductive carbon material, magnetic material, and metallic conductive material. The conductive carbon material may include conductive carbon particles, conductive carbon powder, and/or coke breeze. The metallic conductive material may include steel fibers, and the magnetic material may include taconite. The conductive concrete mixture may also include supplementary cementitious materials (SCM). A method of making a concrete structure includes pouring a concrete mixture to form conductive concrete, and positioning a first conductive screen within the conductive concrete proximate to an exterior surface of the conductive concrete.

Abstract: An in-line fiber-optic temperature sensor is disclosed. In an implementation, the in-line fiber-optic temperature sensor includes an optically transmissive fiber, a reflector, a microstructured fiber defining a channel therein for receiving a fluid, and a Fabry-Perot cavity in fluid communication with the microstructured fiber. The microstructured fiber can be retained between the optically transmissive fiber and the reflector. The Fabry-Perot cavity defined by a material and configured to receive a gas having an index of refraction that changes in a known way with temperature and pressure changes in fluid communication with the channel of the microstructured fiber. The in-line fiber-optic temperature sensor also includes a chamber defined between the optically transmissive fiber and the microstructured fiber for connecting in fluid communication with a vacuum/pressure source for changing pressure.

Abstract: DNA sequences are analyzed using latent semantic analysis. A set of nucleotide sequences is received in which the set has a first number of sequences. A set of basis vectors is determined, in which the set has a second number of basis vectors, the second number being smaller than the first number. Each basis vector represents a specific combination of predetermined nucleotide segments. For each of the nucleotide sequences, an approximate representation of the nucleotide sequence is determined based on a combination of the basis vectors. For each pair of nucleotide sequences, a distance between the pair of nucleotide sequences is determined according the distance between the approximate representation of the pair of nucleotide sequences. The set of nucleotide sequences are classified based on the distances between the pairs of nucleotide sequences.

Abstract: A reactive extrusion process for the production of substituted polysaccharides, in particular, cellulose acetate, starch acetate, carboxymethyl cellulose, and carboxymethyl starch.