The Growth and Survival of Early Instars of \u3ci\u3eBellura Obliqua\u3c/i\u3e (Lepidoptera: Noctuidae) on \u3ci\u3eTypha Latifolia\u3c/i\u3e and \u3ci\u3eTypha Angustifolia\u3c/i\u3e

Larvae of the noctuid moth Bellura obliqua are frequently encountered on Typha latifolia, but less commonly on Typha angustifolia. Experiments were conducted to compare the growth and survivorship of early B. obliqua instars on the two species of cattail. In short-term growth chamber experiments there were no significant differences in the survivorship, relative growth rate (RGR), relative consumption rate (RCR), or the efficiency of conversion of ingested food (ECI) between first-instar larvae reared on leaves of the two species. Third-instar larvae fed stems, however, had a greater RGR and higher ECI when reared on T. lalifolia. Differences in growth are apparently not related to differences in hostplant nitrogen or acid-detergent fiber content. In a long term greenhouse experiment, using transplanted cattails, larvae reared on T. latifolia grew somewhat larger and had a significantly higher survival rate than those reared on T. angustifolia. Host plant structure is postulated to influence larval survivorship. Typha is under consideration for use as a bio-energy crop and planting T. angustifolia may help to reduce infestations in cultivated stands

Core noise measurements on a YF-102 turbofan engine

Core noise from a YF-102 high bypass ratio turbofan engine was investigated through the use of simultaneous measurements of internal fluctuating pressures and far field noise. Acoustic waveguide probes, located in the engine at the compressor exit, in the combustor, at the turbine exit, and in the core nozzle, were employed to measure internal fluctuating pressures. Spectra showed that the internal signals were free of tones, except at high frequency where machinery noise was present. Data obtained over a wide range of engine conditions suggest that below 60% of maximum fan speed the low frequency core noise contributes significantly to the far field noise

Vacuum chamber pressure effects on thrust measurements of low Reynolds number nozzles

Tests were conducted to investigate the effect of vacuum facility pressure on the performance of small thruster nozzles. Thrust measurements of two converging-diverging nozzles with an area ratio of 140 and an orifice plate flowing unheated nitrogen and hydrogen were taken over a wide range of vacuum facility pressures and nozzle throat Reynolds numbers. In the Reynolds number range of 2200 to 12 000 there was no discernable viscous effect on thrust below an ambient to total pressure ratio of 1000. In nearly all cases, flow separation occurred at a pressure ratio of about 1000. This was the upper limit for obtaining an accurate thrust measurement for a conical nozzle with an area ratio of 140

Three-dimensional spatial variations of suspended sediment concentration over vortex ripples

Abstract A three-dimensional mixture theory model (SedMix3D) was used to simulate the flow and sediment transport over vortex ripples for scaled laboratory conditions. SedMix3D treats the fluid-sediment mixture as a continuum of varying density and viscosity with the concentration of sediment and velocity of the mixture calculated using a sediment flux equation coupled to the Navier-Stokes equations for the mixture. Mixture theory allows the model to simulate the three-dimensional flow and sediment concentration within and above an evolving sediment bed. Grid spacing was on the order of a sediment grain diameter and time steps were O(10 -5 s). The simulation was forced with a time series of free-stream velocity measured in a free-surface laboratory flume. Spatial variations in the simulated suspended sediment concentration were primarily associated with the non-uniform generation of vortex structures over the ripple flanks. The suspended sediment was initially picked up in regions of high vorticity, and then caused a damping of the vorticity while being advected through the water column

Simulation of Low-density Nozzle Plumes in Non-zero Ambient Pressures

The direct simulation Monte-Carlo (DSMC) method was applied to the analysis of low-density nitrogen plumes exhausting from a small converging-diverging nozzle into finite ambient pressures. Two cases were considered that simulated actual test conditions in a vacuum facility. The numerical simulations readily captured the complicated flow structure of the overexpanded plumes adjusting to the finite ambient pressures, including Mach disks and barrel shaped shocks. The numerical simulations compared well to experimental data of Rothe

Optimized, diode pumped, Nd:glass, prototype regenerative amplifier for the National Ignition Facility (NIF)

The National Ignition Facility (NIF) will house a 2 MJ Nd:glass laser system to be used for a broad range of inertial confinement fusion experiments. This record high energy laser output will be initiated by a single low energy, fiber -based master oscillator which will be appropriately shaped in time and frequency prior to being split into 48 beams for intermediate amplification. These 48 intermediate energy beams will feed the 192 main amplifier chains. We report on the baseline design and test results for an amplifier subsystem in the intermediate amplifiers. The subsystem is based on a diode pumped, Nd:glass regenerative amplifier. The amplifier is comprised fo a linear, folded, TEM{sub 00}, 4.5m long cavity and represents the highest gain (approximately 10{sup 7}) component in the NIF laser system. Two fundamentally important requirements for this amplifier include output energy of 20 mJ and square pulse distortion of less than 1.45. With a single 48 bar 4.5kW peak power diode array and lens duct assembly we pump a 5 mm diameter X 50 mm long Nd-doped, phosphate glass rod, and amplify the mode matched, temporally shaped (approximately 20ns in duration)oscillator seed pulse to 25 mJof output energy with a very acceptable square pulse distortion of 1.44. This most recent design of the regenerative amplifier has increased the performance and reduced the cost, enabling it to become a solid baseline for the NIF laser system

High fluence 1.05 {mu}m performance tests using 20 ns shaped pulses on the Beamlet prototype laser

Beamlet is a single beamline, nearly full scale physics prototype of the 192 beam Nd:Glass laser driver of the National Ignition Facility. It is used to demonstrate laser performance of the NIF multipass amplifier architecture. Initial system characterization tests have all been performed at pulse durations less than 10 ns. Pinhole closure and modulation at the end of long pulses are a significant concern for the operation of NIF. We recently demonstrated the generation, amplification and propagation of high energy pulses temporally shaped to mimic 20 ns long ignition pulse shapes at fluence levels exceeding the nominal NIF design requirements for Inertial Confinement Fusion by Indirect Drive. We also demonstrated the effectiveness of a new conical pinhole design used in the transport spatial filter to mitigate plasma closure effects and increase closure time to exceed the duration of the 20 ns long pulse

Performance results of the high-gain Nd:glass engineering prototype preamplifier module (PAM) for the National Ignition Facility (NIF)

We describe recent, energetics performance results on the engineering preamplifier module (PAM) prototype located in the front end of the 1.8MJ National Ignition Facility (NIF) laser system. Three vertically mounted subsystem located in the PAM provide laser gain as well as spatial beam shaping. The first subsystem in the PAM prototype is a diode pumped, Nd:glass, linear, TEM{sub 00}, 4.5m long regenerative amplifier cavity. With a single diode pumped head, we amplify a 1nJ, mode matched, temporally shaped ({approx} 20ns) seed pulse by a factor of approximately 10{sup 7} to 20mJ. The second subsystem in the PAM is the beam shaping module, which magnifies the gaussian output beam of the regenerative amplifier to provide a 30mm x 30mm square beam that is spatially shaped in two dimensions to pre-compensate for radial gain profiles in the main amplifiers. The final subsystem in the PAM is the 4-pass amplifier which relay images the 1mJ output of the beam shaper through four gain passes in a {phi}5cm x 48cm flashlamp pumped rod amplifier, amplifying the energy to 175. The system gain of the PAM is 10{sup 10}. Each PAM provides 35 of injected energy to four separate main amplifier chains which in turn delivers 1.8MJ in 192 frequency converted laser beams to the target for a broad range of laser fusion experiments

Integrated operations of the National Ignition Facility (NIF) optical pulse generation development system

We describe the Optical Pulse Generation (OPG) testbed, which is the integration of the MOR and Preamplifier Development Laboratories. We use this OPG testbed to develop and demonstrate the overall capabilites of the NIF laser system front end. We will present the measured energy and power output, temporal and spatial pulse shaping capability, FM bandwidth and dispersion for beam smoothing, and measurements of the pulse-to-pulse power variation of the OPG system and compare these results with the required system performance specifications. We will discuss the models that are used to predict the system performance and how the OPG output requirements flowdown to the subordinate subsystems within the OPG system

Oxygen-permeable microwell device maintains islet mass and integrity during shipping

Islet transplantation is currently the only minimally invasive therapy available for patients with type 1 diabetes that can lead to insulin independence; however, it is limited to only a small number of patients. Although clinical procedures have improved in the isolation and culture of islets, a large number of islets are still lost in the pre-transplant period, limiting the success of this treatment. Moreover, current practice includes islets being prepared at specialized centers, which are sometimes remote to the transplant location. Thus, a critical point of intervention to maintain the quality and quantity of isolated islets is during transportation between isolation centers and the transplanting hospitals, during which 20-40% of functional islets can be lost. The current study investigated the use of an oxygen-permeable PDMS microwell device for long-distance transportation of isolated islets. We demonstrate that the microwell device protected islets from aggregation during transport, maintaining viability and average islet size during shipping.Darling M Rojas-Canales, Michaela Waibel, Aurelien Forget, Daniella Penko, Jodie Nitschke, Fran J Harding, Bahman Delalat, Anton Blencowe, Thomas Loudovaris, Shane T Grey, Helen E Thomas, Thomas W H Kay, Chris J Drogemuller, Nicolas H Voelcker, and Patrick T Coate