Development of Cultured Muscles with Tendon Structures for Modular Bio-Actuators

In this article, we propose a new actuator named the modular bio-actuator (MBA). The MBA has two tendon structures made of polydimethylsiloxane (PDMS) at both ends of the bio-actuator. The MBA can be easily handled and fixed on an artificial micro-robot body to increase its design flexibility and output power. The tendon structures were connected to a bio-actuator in the form of a chain structure, and the connection between the tendon structures and the bio-actuator was maintained for more than three weeks. The contraction length of the MBA was linearly increased when the DC voltage applied to the MBA was increased. The MBA contracted over 200 µm when a DC voltage of 10 V and 1 Hz was applied to the bio-actuator. The output power of the MBA was measured using a PDMS cantilever, and the total output power of the MBA increased linearly when multiple MBAs were stacked on a PDMS cantilever. This study was aimed at improving the design flexibility and controllability of micro-robots and bionic systems.

TUNABLE ULTRA-LONG RANDOM DISTRIBUTED FEEDBACK FIBER LASER

A 72 km open-ended symmetrical tunable random distributed feedback fiber laser (RDB-FL) with different pumping schemes is presented in this study. The random distributed feedback was contributed by Rayleigh scattering in the single-mode fiber while distributed gain was provided by the effect of stimulated Raman scattering. The pumping schemes tested with the configuration was outward and inward pumping, where these would be backward and forward pumping in a non-symmetrical configuration of a fiber laser, respectively. The tuning range was also varied in conjunction with the different pumping schemes to determine the optimum performance. Random lasing in the RDB-FL was achieved by utilizing multiple scattering in the disordered gain medium to achieve resonance. With pump power limited to 1.5 W, the best threshold was measured as low as 1.4 W while the highest total output power was at 8 mW. In outward pumping configuration, the wavelengths that are within the maximum Raman gain (1555-1565 nm) show the best peak powers and total output power with a narrow linewidth, as low as 0.25 nm.

The Power of Wind Turbine Generators Prediction Model Based on Time Series

Author constructed ARIMA model and GARCH model to predict the output power of the 4 wind turbine generators (A, B, C, D) and the total output power of the 4 and 58 wind turbine generators. Whats more, by comparing the results of two methods, it shows that the result of GARCH model is more accurate than ARIMA model in short-term prediction.

Experimental Results of the Superluminescent Fiber Laser Sources for Fiber Optic Sensors

We are presenting experimental work on an erbium-doped fiber operating in the superluminescent regime.Experimental results for different pump power levels and fiber length show that the theoretical and numerical modelcould render useful information for predicting the total output power as a function of fiber doped length and the inputpump power. These types of sources could have direct application in wavelength multiplexed arrangements of fibersensors, fiber gyroscopes or, in general, in any sensors in which a broad wavelength and stable light source isrequired.

Impact of Generator Rating Increase, Ambient Pressure and Coolant Composition and Temperature on Power Generator Heat Exchangers

Heat exchangers’ operating requirements vary depending on several parameters such as plant location, coolant input conditions and generator total output power. Some of these parameters play a more important role than others and understanding these roles is key to designing heat exchangers that will better suit their operating conditions. This paper analytically examines the implications that varying four parameters have on a heat exchanger with a fixed geometry and heat transfer area. Ambient pressure decrease translates into changes on the thermodynamic conditions of the gas flow. Coolant composition variances (from condensate to increased glycol percentages) also play an important role on the exchanger’s heat transfer rates, the higher the glycol percentage the lower the heat transfer rate. In the same manner, the coolant inlet temperature will partly determine heat transfer rates. Lastly, a generator total output power increase will yield higher heat losses on several points of the generator and thus, a higher heat load for the heat exchanger. The graphs and data hereby presented should be of assistance to those designing new coolers as well as those operating current ones.

Variability in Effective Radiating Area at 1 MHz Affects Ultrasound Treatment Intensity

Background and Purpose Previous research has indicated that not all ultrasound transducers heat at equal rates; however, the cause of this disparity is unclear. Variability in spatial average intensity (SAI) has been implicated in this disparity at 3 MHz. This variability has not been explored at 1 MHz. Methods Sixty-six 5-cm2 ultrasound transducers were purchased from 6 different manufacturers. Transducers were calibrated and assessed for effective radiating area (ERA), total output power, and SAI using standardized measurement techniques. Results Total output power values fell within US Food and Drug Administration guidelines, but there were large variations in ERA. The resulting SAI values showed large deviations (−43% to +61%) from the digitally displayed value. Intra-manufacturer SAI values varied up to 53%. Discussion and Conclusion Spatial average intensity can vary largely from the values displayed on these ultrasound generators; in a calibrated cohort, this difference is primarily attributable to differences in measured ERA. Patterns of SAI variability within the manufacturer at 1 MHz do not follow previous reports of variability at 3 MHz.

High Power Lateral Epitaxy MESFET Technology in Silicon Carbide

High impedance silicon carbide power RF transistors are reported, which use the technology of Lateral Epitaxy Metal-Semiconductor FET (LEMES). The LEMES transistor utilizes a heavily doped buried depletion stopper to increase output impedance and breakdown voltage and to eliminate undesirable hot-carrier trapping effects. A power density of 2-3 W/mm at 2 GHz is routinely achieved resulting in a total output power of 10W for packaged components. The value of input and output impedance is around 50 Ohms for a frequency of around 2 GHz.

Solar Concentration of 50,000 Achieved With Output Power Approaching 1 kW

We have achieved a 50,000 ± 3,000 times concentration of sunlight using a unique dielectric nonimaging concentrator in an experiment performed at the National Renewable Energy Laboratory. The scale of the experiment is several times larger than that of previous experiments. Total output power approaching 1 kW passes through a 4.6 mm diameter aperture. An extractor tip is added to the concentrator profile which allows measurement of flux levels using an air calorimeter. This new device has the potential to allow the use of dielectric concentrators at larger scale for thermal electric power generation. We report on the implications of this experiment for the future use of dielectric concentrators.