Preliminary design study - Oxidizer tank helium pressure regulator, Flox-Atlas, airborne Final report

Oxidizer tank helium pressure regulator compatible with fluorine-liquid oxyge

Ilioinguinal and iliohypogastric nerves cannot be selectively blocked by using ultrasound guidance: a volunteer study

Background Ilioinguinal (IL) and iliohypogastric (IH) nerve blocks are used in patients with chronic postherniorrhaphy pain. The present study tested the hypothesis that our method, previously developed in cadavers, blocks the nerves separately and selectively in human volunteers. Methods We blocked the IL and the IH nerves in 16 volunteers in a single-blinded randomized cross-over setting under direct ultrasound visualization, by injecting two times the ED95 volume of 1% mepivacaine needed to block a peripheral nerve. The anaesthetized skin areas were tested by pinprick and marked on the skin. A digital photo was taken. For further analysis, the parameterized picture data were transformed into a standardized and unified coordinate system to compare and calculate the overlap of the anaesthetized skin areas of the two nerves on each side. An overlap <25% was defined as selective block. Results Fifty nerve blocks could be analysed. The mean volume injected to block a single nerve was 0.9 ml. Using ultrasound, we observed spread from one nerve to the other in 12% of cases. The overlap of the anaesthetized skin areas of the nerves was 60.3% and did not differ after exclusion of the cases with visible spread of local anaesthetic from one nerve to the other. Conclusions The IL and IH nerves cannot be selectively blocked even if volumes below 1 ml are used. The most likely explanation is the spread of local anaesthetic from one nerve to the other, although this could not be directly observed in most case

Production and use of metals and oxygen for lunar propulsion

Production, power, and propulsion technologies for using oxygen and metals derived from lunar resources are discussed. The production process is described, and several of the more developed processes are discussed. Power requirements for chemical, thermal, and electrical production methods are compared. The discussion includes potential impact of ongoing power technology programs on lunar production requirements. The performance potential of several possible metal fuels including aluminum, silicon, iron, and titanium are compared. Space propulsion technology in the area of metal/oxygen rocket engines is discussed

Ridge, Moldboard, Chisel, and No-Till Effects on Tile Water Quality beneath Two Cropping Systems

Soil conservation tillage systems, including ridge-tillage, often reduce surface water contamination by pesticides because soil erosion and surface runoff are reduced. However, the effects on losses through subsurface drainage tile are somewhat uncertain. Our field study quantified the effects of four tillage practices in continuous corn (Zea mays L.) and corn-soybean [Glycine max (L.) Merr] rotations on herbicide and nitrate N losses in tile drainage water. Fertilizer and pesticide application methods were uniform for ridge, moldboard, chisel, and no-till systems. Pesticide and nitrate N leaching losses were significantly affected by crop rotation. Tillage practice had little influence on nitrate N and pesticide losses to the subsurface drainage water within a corn-soybean rotation. However, ridge-till and no-till resulted in larger losses of atrazine than the moldboard plow and chisel based systems under continuous corn. Tillage system did not affect the timings of peak tile flow occurrences, although peak tile flow volume was affected by tillage, presumably because each system bad its own macropore system related to preservation or annual destruction of biopores by tillage. Corn yields were significantly higher under corn-soybean rotation than with continuous-corn for all tillage practices. These results indicate that continuous corn production is not an environmentally sustainable practice for this area because it resulted in higher nitrate N leaching losses to groundwater, received higher N-applications, and resulted in lower corn yields than the corn-soybean rotation. The results also reinforce the need for studies on chemical placement, rate, and timing for various tillage practices to reduce tile drainage losses of agricultural chemicals

Quantifying human capital accumulation in rural Ireland in the nineteenth century

Geary and Stark find that Ireland´s Post-Famine per capita GDP converged with British levels, and that this convergence was due to TFP growth rather than mass emigration. We devise new long-run measurements of human capital accumulation in Ireland in order to facilitate an assessment of sources of this TFP growth, including the relative contribution of men and women. We do so by exploiting the frequency at which age data heap at round ages, a measure that has been widely interpreted as an indicator of a population´s basic numeracy skills. Because Földvári, Van Leeuwen and Van Leeuwen-Li find that gender-specific trends in this measure derived from census returns are biased by who is reporting and recording the age information, we correct any computed numeracy trends using data from prison and workhouse registers, sources in which women self-reported their age. We find that rural Irish women born early in the nineteenth century had substantially lower levels of human capital than uncorrected census data would otherwise suggest. Our results are large in magnitude and economically significant. The speed at which women converged is consistent with Geary and Stark´s interpretation of Irish economic history; Ireland likely graduated to Europe´s club of advanced economies thanks in part to rapid advances in female human capital

The spin vector of Venus determined from Magellan data

A control network of the north polar region of Venus has been established by selecting and measuring control points on full-resolution radar strips. The measurements were incorporated into a least-squares adjustment program that improved initial estimates of the coordinates of the control points, pole direction, and rotation rate of Venus. The current dataset contains 4206 measurements of 606 points on 619 radar strips. The accuracy of the determination is driven by spacecraft ephemeris errors. An accurate estimate of the rotation period of Venus was obtained by applying an ephemeris improvement technique. The second cycle closure orbits improved ephemeris solutions for 40 orbits (376-384, 520-528, 588-592, 658-668, 1002-1010, 1408-1412, 1746-1764, and 2166-2170) are included and fixed in the geodetic control computations, thus trying the network to the J2000 coordinate system

Effect of electric field on the photoluminescence of polymer-inorganic nanoparticles composites

We report on the effect of electric field on the photoluminescence, PL, from a composite consisting of a conjugated polymer mixed with zinc oxide nanoparticles. We have found that in the absence of electric field PL emission from the composite film has two maxima in the blue and green-yellow regions. Application of a voltage bias to planar gold electrodes suppresses the green-yellow emission and shifts the only PL emission maximum towards the blue region. Current-voltage characteristics of the polymer-nanoparticles composite exhibit the non-linear behavior typical of non-homogeneous polymer-inorganic structures. Generation of excited states in the composite structure implies the presence of several radiative recombination mechanisms including formation of polymer-nanoparticle complexes including exciplex states and charge transfer between the polymer and nanoparticle that can be controlled by an electric field.Comment: 5 pages, 5 figures. accepted for publication in Solid State Communication