The seasonal abundance of epilithic algae was correlated with major fhysico-chemical parameters in a firstorder, heavily shaded stream in northern Arizona. Diatoms made up over 85%, by numerical abundance, of the epilithon community Light energy, water temperature, and stream discharge were most highly correlated with seasonal abundance of epilithic diatom taxa when analyzed with stepwise multiple regression. None of the chemical variables measured in the study (NO, " 0-PO,, 5 0 , including PH) was found to be sign$cantly correlated with the seasonal community structure of epilithic diatoms. Total diatom cell densities showed a signijcant negative correlation to stream bed light energy!. Likewise, total diatom cell densities along a transect in the stream bed showed a negative correlation to current velocity during those months when basejow was low and stable, and current velocity was 1 2 5 cm.sec-'. Most diatom taxa had highest cell densities at temperatures 16°C and at daily mean stream bed light levels < 400 PE ' m-2. s-l. Highest cell densities ofgreen algae occurred at temperatures between 6-16" C and at daily mean stream bed light levels of ,400 P E . m-2. s-l. Blue-green algae (cyanobacteria) grew best at the highest recorded water temperatures and daily mean stream bed light energy (16-20°C and 900-1200 hE.m-2.s-1), Abrupt increases in NO,-N coincided with a brief pulse of Nostoc pruniforme colonies during June, and leaf drop from Alnus oblongi folia during October.

Abstruct-A 100-element hybrid grid amplifier has been fabricated. The active devices in the grid are custom-made pseudoransistor (pHEMT) differentialfor gain analysis and compare rid includes stabilizing resistors the grid has a peak gain of 10 a gain of 12 dB when tuned for andwidth is 15% at 9 GHz. The m~n i~u m noise figure is 3 dB. The maximum saturated output power is 3.7 W, with a peak power-added efficiency of 12%. are a significant improvement over previous grid ed on heterojunction bipolar transistors (HBT's).The maximum ljlput &=am E

Weight 85 lbs plus payload Rigging Main + Jib "storm" sails and chafe resistant lines Mast Unstayed reinforced carbon Winch Electric with anti-jamming spool Rudder and Keel No-tangle design sheds lines and seaweed Power 12 V, 35 W solar array Batteries Up to 120 Ah LiFePO 4 Standard sensors GPS, PRH, Meteorological, AIS (passive receiver on ASV for informing the operator of the location of nearby ships via the iPad application) Optional sensors Water quality: O 2 , CT, backscatter, 3/6 channel fluorometer (chl. a, phycocyanin, phycoerythrin, CDOM, turbidity, oil) Acoustic: Pinger Tracking, Cetaceans, Telemetry Custom: ADCP and many others Navigation Autonomous to waypoints + manual option Charts NOAA RNC included UI Chart based iOS App + web portal Dashboard Location, speed, course, heading, true and apparent wind, pitch, roll, power, battery and solar voltage, sail and rudder position, thruster RPM, connectivity status, waypoint ETA Comms Iridium SBD (Sat), Cell, and WiFi Real-time Configurable telemetry and sensor data

No abstract

Cross-sectional transmission electron microscopy was used to determine the growth kinetics of silicide films in the Cr/(100)Si system. Growth rate, growth mechanisms, and structural details were obtained from direct observation of the reacted layer after various time intervals. At 425 °C, CrSi2 was the only phase formed; its growth was diffusion-limited, with a rate constant of 6.2×10−13 cm2/s. A thin oxide layer (∼20 Å) at the Cr/Si interface did not prevent silicide growth at 425 °C, but it served as an immobile marker, which confirmed that Si was the main diffusing species.