Abstract: A shell and tube heat exchanger has elongated shell having first and second opposing ends and an open interior. A core divides the open interior of the shell into first and second enclosed portions. The shell has first and second tube fluid openings at opposing ends. End plates divide the first and second enclosed portions into manifold portions and enclosed shell chamber portions. Tubes extend from the end plates, through the enclosed shell chambers to the core. Shell fluid openings are at sides of the elongated shell, a first fluid opening communicating with the first shell chamber, and a second fluid opening communicating with the second shell chamber. The shell has a long axis, and the end plates are angled relative to the long axis. The tubes are polygonal with rounded corners and straight sides. The heat exchanger can be used for both evaporation and condensation processes.

Abstract: A shell and tube heat exchanger has elongated shell having first and second opposing ends and an open interior. A core divides the open interior of the shell into first and second enclosed portions. The shell has first and second tube fluid openings at opposing ends. End plates divide the first and second enclosed portions into manifold portions and enclosed shell chamber portions. Tubes extend from the end plates, through the enclosed shell chambers to the core. Shell fluid openings are at sides of the elongated shell, a first fluid opening communicating with the first shell chamber, and a second fluid opening communicating with the second shell chamber. The shell has a long axis, and the end plates are angled relative to the long axis. The tubes are polygonal with rounded corners and straight sides. The heat exchanger can be used for both evaporation and condensation processes.

Abstract: The present disclosure concerns embodiments of aluminum alloy compositions exhibiting superior microstructural stability and strength at high temperatures. The disclosed aluminum alloy compositions comprise particular combinations of components that contribute the ability of the alloys to exhibit improved microstructural stability and hot tearing resistance as compared to conventional alloys. Also disclosed herein are embodiments of methods of making and using the alloys.

Abstract: The present disclosure concerns embodiments of aluminum alloy compositions exhibiting superior microstructural stability and strength at high temperatures. The disclosed aluminum alloy compositions comprise particular combinations of components that contribute the ability of the alloys to exhibit improved microstructural stability and hot tearing resistance as compared to conventional alloys. Also disclosed herein are embodiments of methods of making and using the alloys.

Abstract: Systems and methods for synthesizing continuous graphene sheets are provided. The systems and methods include passing a catalyst substrate through a heated chemical vapor deposition chamber and exposing the substrate to a reaction gas mixture of hydrogen and hydrocarbon at a preselected location within the chamber. The reaction gas mixture can include hydrogen having a partial pressure of between about 0 Torr and 20 Torr, hydrocarbon having a partial pressure of between about 20 mTorr and about 10 Torr, and one or more buffer gases. The buffer gases can include argon or other noble gases to maintain atmospheric pressure within the chemical deposition chamber. The resulting graphene can be made with continuous mono and multilayers (up to six layers) and have single crystalline hexagonal grains with a preselected nucleation density and domain size for a range of applications.

Abstract: A system and a method for characterizing a dielectric material are provided. The system and method generally include applying an excitation signal to electrodes on opposing sides of the dielectric material to evaluate a property of the dielectric material. The method can further include measuring the capacitive impedance across the dielectric material, and determining a variation in the capacitive impedance with respect to either or both of a time domain and a frequency domain. The measured property can include pore size and surface imperfections. The method can still further include modifying a processing parameter as the dielectric material is formed in response to the detected variations in the capacitive impedance, which can correspond to a non-uniformity in the dielectric material.

Abstract: A system and a method for characterizing a dielectric material are provided. The system and method generally include applying an excitation signal to electrodes on opposing sides of the dielectric material to evaluate a property of the dielectric material. The method can further include measuring the capacitive impedance across the dielectric material, and determining a variation in the capacitive impedance with respect to either or both of a time domain and a frequency domain. The measured property can include pore size and surface imperfections. The method can still further include modifying a processing parameter as the dielectric material is formed in response to the detected variations in the capacitive impedance, which can correspond to a non-uniformity in the dielectric material.

Abstract: A method of drying casted slurries that includes calculating drying conditions from an experimental model for a cast slurry and forming a cast film. An infrared heating probe is positioned on one side of the casted slurry and a thermal probe is positioned on an opposing side of the casted slurry. The infrared heating probe may control the temperature of the casted slurry during drying. The casted slurry may be observed with an optical microscope, while applying the drying conditions from the experimental model. Observing the casted slurry includes detecting the incidence of micro-structural changes in the casted slurry during drying to determine if the drying conditions from the experimental model are optimal.

Abstract: A method of making a cathode for a battery includes the steps of depositing a precursor cathode film having a first crystallinity profile. The precursor cathode film is annealed by irradiating the precursor cathode film with from 1 to 100 photonic pulses having a wavelength of from 200 nm to 1600 nm, a pulse duration of from 0.01 ?s and 5000 ?s and a pulse frequency of from 1 nHz to 100 Hz. The photonic pulses are continued until the precursor cathode film has recrystallized from the first crystallinity profile to a second crystallinity profile.

Abstract: A method for bandgap shift and phase transformation for titania structures. The method can include providing a flexible substrate, depositing a titania film onto the substrate, and exposing the titania film to one or more pulses of infrared energy of sufficient energy density and for a sufficient time to crystallize the titania film to predominantly anatase crystalline phase. The flexible substrate can be formed from a polymeric material, and the method can achieve a bandgap shift from greater than 3.0 eV to approximately 2.4 eV. The method can also include forming a crystalline titania layer over a substrate and annealing the crystalline titania layer by applying pulsed thermal energy sufficient to modify the phase constitution of the crystalline titania layer. The source of pulsed thermal energy can include an infrared flashlamp or laser, and the resulting titania structure can be used with photovoltaic and photoelectrolysis systems.