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We demonstrate a distributed feedback (DFB) semiconductor laser based on i-line lithography and surface periodic current injection technologies with a lasing wavelength of 795 nm, which corresponds to the D1 spectrum of Rb and has many applications with respect to alkali vapor lasers and atomic clocks. The maximum output power, side mode suppression ratio (SMSR), and single-longitudinal-mode tunable range of our device are 50.89 mW (at 20 °C), 34.56 dB, and 12.792 nm, respectively. The rate of change in wavelength with temperature of the laser is 0.401 nm/°C, which is equivalent to that of a Fabry-Perot (FP) laser and much better than that of a general DFB device. This device has a cavity the same as an FP laser without any etching gratings, meanwhile the lasing spectrum behaves a single longitudinal mode characteristic as a DFB laser.

Influence of pulse and reverse current on the composition, physical-mechanical and functional properties of Ag-W coatings was studed. It's established that adding tungsten oxides to composition of silver coating, depositing with pulse and reverse currents allow to reduce a grit size, to increase microhardness and wear resistance. Depositing of coatings with periodic currents increases a process efficiency and expands a technological capabilities of the electrophysical properties control of the electroplated composite coatings.

We demonstrate a distributed feedback (DFB) semiconductor laser based on i-line lithography and surface periodic current injection technologies with a lasing wavelength of 795 nm, which corresponds to the D1 spectrum of Rb and has many applications with respect to alkali vapor lasers and atomic clocks. The maximum output power, side mode suppression ratio (SMSR), and single-longitudinal-mode tunable range of our device are 50.89 mW (at 20 °C), 34.56 dB, and 12.792 nm, respectively. The rate of change in wavelength with temperature of the laser is 0.401 nm/°C, which is equivalent to that of a Fabry-Perot (FP) laser and much better than that of a general DFB device. This device has a cavity the same as an FP laser without any etching gratings, meanwhile the lasing spectrum behaves a single longitudinal mode characteristic as a DFB laser. [ABSTRACT FROM AUTHOR]

Introduction Systemic sclerosis (SSc) is a rare disease affecting digital microcirculation, leading to finger ulcers and in some cases to amputation. Prostacyclin analogues can be used intravenously but their therapeutic effect is counterbalanced by potentially serious vasodilatation-induced side effects. Iontophoresis of treprostinil could be a promising local therapeutic alternative for SSc-related digital ulcers. Iontophoretic drug delivery is complex, and whether continuous or periodic current should be used remains debated. The objective of the present work is to compare the effect of continuous vs pulsed iontophoresis of treprostinil in rats. Materials and methods Treprostinil (0.64 mM and 0.064 mM) and NaCl were delivered by cathodal iontophoresis onto the hindquarters of anaesthetized rats. Three protocols delivering the same quantity of current were compared: one was continuous (100 μA during 20 min) and two were periodic (B: twenty 1-min cycles with 200 μA during 30 s followed by 30 s Off; and C: twenty 1-min cycles with 600 μA during 10 s followed by 50 s Off) ( n = 8 for each protocol with each concentration). Skin blood flow was quantified using laser Doppler imaging and skin resistance was calculated with Ohm’s law. Results All protocols induced a significant increase in skin blood flow. At the lower concentration (0.064 mM treprostinil) the pulsed 10/50 sequence significantly enhanced cutaneous blood flow ( Table 1 ; Fig. 1 B) compared to continuous iontophoresis or the 30/30 sequence. We noted that the pulsed iontophoresis of NaCl (10/50 sequence) induced a significant early increase in cutaneous blood flow in comparison with continuous iontophoresis. Skin resistance measures were negatively correlated with current intensity delivered. Conclusion In conclusion, pulsed iontophoresis of treprostinil with a 10 s/50 s (On/Off) protocol at 600 μA increases the efficacy of iontophoresis at 0.064 mM but not at a tenfold higher concentration. Pulsed iontophoresis could be used to optimize treprostinil iontophoresis, to provide similar efficacy with decreased costs, and should now be tested on humans. [ABSTRACT FROM AUTHOR]

Thermal waves induced in a thermoelectric (TE) element by periodic current pulses are studied. An analytical description is obtained in the form of a Fourier series. Different combinations of current pulses and frequencies are reviewed. The utmost performance of a TE thermal cycler is estimated. [ABSTRACT FROM AUTHOR]

An Acoustic Doppler Current Profiler (ADCP) was deployed for 83 days at the bottom of Uchiumi Bay in the Bungo Channel, Japan. At the same station, the water temperature was measured at nine layers using a thermistor chain. From the temporal variations of the backscatter signal strength data of ADCP, we found that the backscatter signal intensity occasionally showed day-to-night fluctuations. We deduced that the day-to-night fluctuations suggested characterizations of migration patterns of zooplankton or krill, because the signal intensity became relatively high during the night. The migration pattern tended to occur after a cold-water intrusion from the shelf slope region south of the Bungo Channel, which is known as a ‘ bottom intrusion ’. The bottom intrusion occurred six times during the observation period, and the tendency for the diurnal signal in the back scatter signal strength to develop after the bottom intrusion was observed in four of six cases. Though specific biological effects caused by the bottom intrusion are still unclear, the occasional diurnal fluctuations in backscatter signal strength may indicate that the bottom intrusion affects the biological environment in Uchiumi Bay, because the diurnal signal tended to intensify only after the bottom intrusion. [Copyright &y& Elsevier]