14,396 research outputs found
Alignment apparatus using a laser having a gravitationally sensitive cavity reflector
A description is given of a device for determining a true gravitational vertical. The apparatus is composed of a vertically disposed laser with a gravitationally sensitive lower regeneration reflector. The reflector enables an output beam to be developed only when the optical axis of the laser is disposed normal to the gravitationally sensitive reflective surface. In an alternative embodiment, the devices is combined with a servo system to provide a gravitationally stabilized horizontal platform
Estimate of CP Violation for the LBNE Project and $\delta_{CP}
Measurements of CP violation (CPV) and the basic parameter are
the goals of the LBNE Project, which is being planned. Using the expected
energy and baseline parameters for the LBNE Project, CPV and the dependence of
CPV on are estimated, to help in the planning of this project.Comment: 7 pages, 1 figur
A novel laser ranging system for measurement of ground-to-satellite distances
A technique was developed for improving the precision of laser ranging measurements of ground-to-satellite distances. The method employs a mode-locked laser transmitter and utilizes an image converter tube equipped with deflection plates in measuring the time of flight of the laser pulse to a distant retroreflector and back. Samples of the outgoing and returning light pulses are focussed on the photocathode of the image converter tube, whose deflection plates are driven by a high-voltage 120 MHz sine wave derived from a very stable oscillator. From the relative positions of the images produced at the output phosphor by the two light pulses, it is possible to make a precise determination of the fractional amount by which the time of flight exceeds some large integral multiple of the period of the deflection sinusoid
A Check-list and identification key for succulent plants in general cultivation in Nairobi
Volume: 8
Emerging role of the KCNT1 Slack channel in intellectual disability
The sodium-activated potassium KNa channels Slack and Slick are encoded by KCNT1 and KCNT2, respectively. These channels are found in neurons throughout the brain, and are responsible for a delayed outward current termed IKNa. These currents integrate into shaping neuronal excitability, as well as adaptation in response to maintained stimulation. Abnormal Slack channel activity may play a role in Fragile X syndrome, the most common cause for intellectual disability and inherited autism. Slack channels interact directly with the Fragile X Mental Retardation protein (FMRP) and IKNa is reduced in animal models of Fragile X syndrome that lack FMRP. Human Slack mutations that alter channel activity can also lead to intellectual disability, as has been found for several childhood epileptic disorders. Ongoing research is elucidating the relationship between mutant Slack channel activity, development of early onset epilepsies and intellectual impairment. This review describes the emerging role of Slack channels in intellectual disability, coupled with an overview of the physiological role of neuronal IKNa currents
Computer recommendations for an automatic approach and landing system for V/STOL aircraft. Volume 1 - Computer recommendations
Evaluation of digital computer for V/STOL aircraft automatic approach and landing syste
Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels
The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described
Correlation of effects of fuel-air ratio, compression ratio, and inlet-air temperature on knock limits of aviation fuels
Hepatic artery thrombosis after pediatric liver transplantation a medical or surgical event
Hepatic artery thrombosis (HAT) is one of the most serious complications after orthotopic liver transplan¬tation, and is associated with a high morbidity and mor¬tality. This study retrospectively reviewed 66 liver transplants in children under the age of 10 years during1 a year-long period at a single institution.;A, total of 28 perioperative variables were analyzed to identify responsible factors of HAT. Of the 66 children, 18 (26%) developed HAT within 15 days after the transplant (HAT group); 29 (42%) had an uneventful postoperative course (control group). To avoid the possible influence of other complications 19 patients were excluded. Of the variables compared between the 2 study groups, three surgical factors (diameter of the hepatic artery-- greater or less than 3 mm; type of arterial anastomosis—end-to-end versus the use of an iliac graft or aortic conduit; and number of times the anastomosis was redone--one versus more than one), were found to be significantly different (P<.05) between HAT and control groups. Two medical factors also were significantly different: the use of intraoperative transfusion of fresh frozen plasma (FFP) and the administration of postoperative prophylactic anticoagulant treatment. A heparin and dextran-40 protocol appeared to be effective in preventing HAT (P<.02). Moreover, after multivariate analysis, anticoagulation therapy was demonstrated to with poor hepatic artery flow. © 1989 by The Williams and Wilkins Co
Excitation Energy Dependence of the Exciton Inner Ring
We report on the excitation energy dependence of the inner ring in the
exciton emission pattern. The contrast of the inner ring is found to decrease
with lowering excitation energy. Excitation by light tuned to the direct
exciton resonance is found to effectively suppress excitation-induced heating
of indirect excitons and facilitate the realization of a cold and dense exciton
gas. The excitation energy dependence of the inner ring is explained in terms
of exciton transport and cooling.Comment: 5 pages, 4 figure
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