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To enhance the packing density of composite cathode for all-solid-state lithium-ion batteries, the effect of a bimodal sized solid electrolyte was studied. The composite cathode, which is fabricated using the powder compression method, consisted of the cathode active material, a conductive agent, and the solid electrolyte. However, the composite cathode construction had voids. The voids in the composite cathode were restricted to ionic conduction between the cathode active materials and the solid electrolytes. Suppression of the voids in the composite cathode improved the electrochemical performance of the all-solid-state battery. A composite cathode using bimodal sized electrolyte powders demonstrated better cell performance than that using only fine or coarse sized electrolyte powders. These results demonstrated that the composite cathode using the bimodal sized electrolyte enhanced the electrochemical performance of the all-solid-state battery because it improved the packing density of the cathode.

Atomically smooth, single crystalline Bi 2 Se 3 thin films were grown on a Ge(1 1 1) substrate using molecular beam epitaxy. Crystallinities of both the surface and the bulk as well as the stoichiometry of the grown film were characterized by using low-energy electron diffraction, scanning tunneling microscopy, X-ray diffraction, and photoelectron spectroscopies. Hexagonal atomic structures, quintuple layer steps observed in STM images confirmed that the Bi 2 Se 3 film with a (0 0 0 1) surface was grown. Diffraction peak positions as well as the chemical composition determined from the core-level photoelectron spectra coincide well with those expected for the Bi 2 Se 3 crystal. The surface state with a Dirac cone was observed in the valence photoelectron spectra, which also support that a high-quality Bi 2 Se 3 film was grown on the Ge(1 1 1) substrate. The interface between Ge(1 1 1) and Bi 2 Se 3 (0 0 0 1) is expected to be abrupt due to the small lattice between them.

The influence of Pb atoms adsorbed on an In/Si(111) surface on the phase transition was investigated by using low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). LEED data showed that the transition temperature for the 4×1 → 8×2 structural phase transition decreased in proportion to the amount of Pb deposition. The Pb adatoms appeared as bright protrusions in an STM image taken at 90 K, suggesting that they were located high above the In atomic wires. The regions surrounding the Pb adatoms remained in the 4×1 phase while the other areas turned into the 8×2 or 4×2 phase at this temperature below the transition temperature. Near each Pb adatom, a Friedel-oscillation-like modulation with a double (×2) periodicity in the wire direction was developed. This ×2 modulation was found to be different in nature from the low-temperature 8×2 (or 4×2) phase. We suggest that a Pb-adatom-induced deep potential well is responsible for the Tc lowering and the ×2 modulation.

This paper proposes an improved stator flux estimator through ensuring conventional PLPF to act as a pure integrator for sensorless control of induction motors. Conventional PLPF uses the estimated synchronous speed as a cut-off frequency and has the gain and phase compensators. The gain and phase compensators are determined on the assumption that the estimated synchronous angular speed is coincident with the real speed. Therefore, if the synchronous angular speed is not same as the real speed, the gain and phase compensation will not be appropriate. To overcome the problem of conventional PLPF, this paper analyzes the relationship between the synchronous speed error and the phase lag error of the stator flux. Based on the analysis, this paper proposes the synchronous speed error compensation scheme. To achieve a start-up without speed sensor, the current model is used as the stator flux estimator at the standstill. When the motor starts up, the current model should be switched into the voltage model. So a stable transition between the voltage model and the current model is required. This paper proposes the simple transition method which determines the initial values of the voltage model and the current model at the transition moment. The validity of the proposed schemes is proved through the simulation results and the experimental results.

A novel miniaturization technology for binary-fluid heat and mass exchange was developed and numerous components were fabricated for demonstration as different parts of an ammonia/water absorption heat pump. Short lengths of microchannel tubes are placed in an array, with several such arrays stacked vertically. The ammonia/water solution flows in falling film/droplet mode on the outside of the tubes while coupling fluid flows through the microchannels. Coupling fluid heat transfer coefficients are extremely high due to the use of microchannel tubes. Effective vapor–solution contact on the absorption side minimizes heat and mass transfer resistances. This concept addresses all the requirements for absorber design in an extremely compact geometry. The technology is suitable for almost all absorption heat pump components (absorbers, desorbers, condensers, rectifiers, and evaporators) and for a wide range of binary-fluid processes. The development of several components for absorption and desorption at different capacities using this technology is reported here.

In this paper, the way to compensate for flux error caused by estimated stator resistance error will be suggested when PLPF is utilized as flux estimator, which is used for sensorless vector control of induction motor. For the highly efficient sensorless control, flux estimation method using PLPF has been widely used. To accurately obtain flux using PLPF, it is significant to estimate synchronous angular velocity. Therefore, the way to make use of PLPF's phase lag error has been suggested; however, to be more accurate, flux magnitude error should be seriously considered and compensated. Error of flux magnitude usually takes place because of estimation error of stator resistance. For this reason, this paper works out a way to make up for the flux magnitude error while using PLPF and it would be proved with simulations and experimental results.

In this paper, the improved stator flux estimator has been proposed to ensure a Programmable Low Pass Filter (PLPF) to act as a pure integrator for sensorless control of induction motors. In a conventional PLPF, the estimated synchronous angular speed is used as a cutoff frequency of a PLPF whose gain and phase compensator is determined on the assumption of the estimated synchronous angular speed being coincident with the actual one. However, if the synchronous angular speed is not exactly estimated, the gain and phase compensation will not be appropriate. To overcome the mentioned problem, this paper analyzes the relation between the synchronous speed error and the phase lag error of the stator flux. Based on the analysis, the synchronous speed error compensation scheme is proposed. For a sensorless start-up, the current model is used as the stator flux estimator at the standstill. Therefore, a stable transition between the voltage model and the current model is required. This paper proposes the simple transition method which determines the initial values of the voltage model and the current model at the transition moment. The validity of the proposed schemes is proved through simulation results and experimental results.

In this paper, the improved stator flux estimator has been proposed to ensure A Programmable Low Pass Filter (PLPF) to act as a pure integrator for sensorless control of induction motors. Conventional PLPF uses the estimated synchronous speed as a cut-off frequency, with the magnitude and phase compensator determined on the assumption of the estimated synchronous speed being coincident with the actual one. However, if the synchronous speed is not exactly estimated, the magnitude and phase compensation will not be appropriate. Therefore, this paper has analyzed the relation between the synchronous speed error and the phase lag error of the stator flux. Based on this analysis, the synchronous speed error compensation scheme is proposed. In addition, this paper proposes the flux error compensation scheme because there still remain errors in spite of the speed error compensation. The validity of the proposed estimator has been proven using the simulation results.

In this paper, the improved stator flux estimator is proposed to ensure a programmable low pass filter (PLPF) to act as a pure integrator for sensorless control of induction motor. The estimated synchronous angular speed is used as a pole of a PLPF whose gain and phase compensator is determined on the assumption of the estimated synchronous angular speed being coincident with the actual one. However, if the synchronous angular speed is not exactly estimated, the gain and phase compensation will not be appropriate. To overcome the mentioned problem, this paper analyzes the relation between the synchronous speed error and the phase lag error of the stator flux. Based on the analysis, the synchronous speed error compensation scheme is proposed. For a sensorless start-up, this paper utilizes the current model as a flux estimator at the standstill. When the current model is switched to the voltage model, large fluctuations in the stator flux and the motor speed can be caused. Therefore, the simple method for a smooth transition between two models is proposed. Validity of the proposed schemes is verified through both simulation results and experimental results.

Heat and mass transfer in a permeable fabric system used for Personal Protective Equipment (PPE) was investigated using hot air jet impingement conditions to mimic the jet exhaust of Short Take-Off and Vertical Landing (STOVL) aircraft. The STOVL aircraft uses a thrust-vectoring nozzle of the jet engine and a lift fan in order to vertically land and take off a short runaway. The jet engine exhaust is a new kind of thermal hazard for military personnel operating within an affected zone of the jet exhaust. An experimental approach was used to measure the thermal response of a fabric system consisting of permeable fabric samples and air pocket using a high-speed jet impingement. The jet impingement conditions consisted of two different temperatures: one of 100°C and another of 200°C at a jet impingement velocity of 32 m/s. Air was used as the working fluid. In this study, two permeable fabrics, (NOMEX IIIA and Cotton) commonly used for the Personal Protective Equipment (PPE) were investigated. The physical properties (porosity, permeability, Ergun coefficient, and density) and the thermo-physical properties (thermal diffusivity, thermal conductivity, and specific heat) of the fabrics were measured. A one-dimensional, two-medium formulation assuming thermal non-equilibrium between solid (fabric) and gas (air) phases in the fabric layer was used for the numerical analysis. The measurement results from the fabric experiment were used to define boundary conditions and adjust various heat transfer correlations and input data used in the numerical model. The experimental and numerical results of the temperatures of the fabric system were compared. The effects of the air temperature of the jet impingement on the thermal response of the fabric system were discussed.

We propose PPVR, a power-aware position vector routing protocol for wireless sensor networks. PPVR is an energy efficient geographical routing protocol that improves existing geographic routing protocols in two ways. First, in the forwarding phase, PPVR reduces the transmission energy by passing packets through a relay node called a power-aware node. Second, PPVR provides an efficient void node avoidance scheme that mitigates the cases forwarding packets to a wrong path so that higher route discovery success rate is achieved. The simulation results shows that the PPVR outperforms existing geographic routing protocols including GPSR and GEAR, in terms of the energy consumption and the successful delivery rate.