1,265 research outputs found
Hyperbola-generator for location of aperiodic events
Plotting device, when used in conjunction with three or more detectors and local receiver and recorder, can quickly pinpoint location of any aperiodic event. Operation requires minimal training and is readily adapted to the field. Mechanical error in device prototype is less than or equal to 3 percent
Modulated infrared radiant source
A modulated, infrared radiant energy source was developed to calibrate an airborne nadir-viewing pressure modulated radiometer to be used to detect from Earth orbit trace gases in the troposphere. The technique used an 8 cm long, 0.005 cm diameter platinum-iridium wire as an isothermal, thin line radiant energy source maintained at 1200 K. A + or - 20 K signal, oscillating at controllable frequencies from dc to 20 Hz, was superimposed on it. This periodic variation of the line source energy was used to verify the pressure modulated radiometer's capability to distinguish between the signal variations caused by the Earth's background surface and the signal from the atmospheric gases of interest
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Proposed Keystone XL Pipeline: Legal Issues
[Excerpt] In 2008, TransCanada Corp. applied for a presidential permit from the State Department to construct and operate an oil pipeline across the U.S.-Canada border in a project known as Keystone XL. The Keystone XL pipeline would transport oil produced from oil sands in Alberta,Canada, to Gulf Coast refineries. The permit application was subjected to review by the State Department pursuant to executive branch authority over cross-border pipeline facilities as articulated in Executive Order 13337.
After several phases of review, on November 10, 2011, the State Department announced that it would seek additional information about alternative pipeline routes before it could move forward with a national interest determination. In response, several pieces of legislation were introduced, including Title V of the Temporary Payroll Tax Cut Continuation Act of 2011. Title V dictated that President must grant the Keystone XL pipeline permit within 60 days of the law’s enactment, unless the President determined that the pipeline is not in the national interest. If the President did not make a national interest determination and took no action to grant the permit, then the law provided that the permit “shall be in effect by operation of law.” The Temporary Payroll Tax Cut Continuation Act of 2011 (P.L. 112-78), including Title V addressing the Keystone XL permit, was enacted on December 23, 2011.
Pursuant to the requirements of Title V, on January 18, 2012, the State Department recommended that “the presidential permit for the proposed Keystone XL pipeline be denied and, that at this time, the TransCanada Keystone XL Pipeline be determined not to serve the national interest. ”The same day, the President stated his determination that the Keystone XL pipeline project“ would not serve the national interest.
”New legislative activity with respect to the permitting of border-crossing facilities, a subject previously handled exclusively by the executive branch, has triggered inquiries as to whether this raises constitutional issues related to the jurisdiction of the two branches over such facilities. Additionally, as states have begun to contemplate taking action with respect to the pipeline siting, some have questioned whether state siting of a pipeline is preempted by federal law. Others argue that states dictating the route of the pipeline violates the dormant Commerce Clause of the Constitution which, among other things, prohibits one state from acting to protect its own interests to the detriment of other states.
This report reviews those legal issues. First, it suggests that legislation related to cross-border facility permitting is unlikely to raise significant constitutional questions, despite the fact that such permits have traditionally been handled by the executive branch alone pursuant to its constitutional “foreign affairs” authority. Next, it observes generally that state oversight of pipeline siting decisions does not appear to violate existing federal law or the Constitution. Finally, the report suggests that State Department’s implementation of the existing authority to issue presidential permits appears to allow for judicial review of its National Environmental Policy Act determinations
Kinetic simulations of X-B and O-X-B mode conversion
We have performed fully-kinetic simulations of X-B and O-X-B mode conversion
in one and two dimensional setups using the PIC code EPOCH. We have recovered
the linear dispersion relation for electron Bernstein waves by employing
relatively low amplitude incoming waves. The setups presented here can be used
to study non-linear regimes of X-B and O-X-B mode conversion.Comment: 4 pages, 3 figure
Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U
The Synthetic Aperture Microwave Imaging (SAMI) system is a novel diagnostic consisting of an array of 8 independently-phased antennas. At any one time, SAMI operates at one of 16 frequencies in the range 10-34.5GHz. The imaging beam is steered in software post-shot to create a picture of the entire emission surface. In SAMI’s active probing mode of operation, the plasma edge is illuminated with a monochromatic source and SAMI reconstructs an image of the Doppler back-scattered (DBS) signal. By assuming that density fluctuations are extended along magnetic field lines, and knowing that the strongest back-scattered signals are directed perpendicular to the density fluctuations, SAMI’s 2-D DBS imaging capability can be used to measure the pitch of the edge magnetic field. In this paper we present preliminary pitch angle measurements obtained by SAMI on the Mega-Amp Spherical Tokamak (MAST) at Culham Centre for Fusion Energy and on the National Spherical Torus Experiment Upgrade at Princeton Plasma Physics Laboratory. The results demonstrate encouraging agreement between SAMI and other independent measurements
Comparison of V-4 and V-5 Exercise/Oxygen Prebreathe Protocols to Support Extravehicular Activity in Microgravity
The Prebreathe Reduction Program (PRP) used exercise during oxygen prebreathe to reduce necessary prebreathe time prior to depressurizing to work in a 4.3 psi suit during extravehicular activity (EVA). Initial testing produced a two-hour protocol incorporating ergometry exercise and a 30 min cycle of depress/repress to 10.2 psi where subjects breathed 26.5% oxygen/balance nitrogen (Phase II - 10 min at 75% peak oxygen consumption [VO2 peak] followed by 40 min intermittent light exercise [ILE] [approx. 5.8 mL-per kilogram- per minute], then 50 min of rest). The Phase II protocol (0/45 DCS) was approved for operations and has been used on 40 EVAs, providing significant time savings compared to the standard 4 h resting oxygen prebreathe. The Phase V effort focused on performing all light in-suit exercise. Two oxygen prebreathe protocols were tested sequentially: V-4) 160 min prebreathe with 150 min of continuous ILE. The entire protocol was completed at 14.7 psi. All exercise involved upper body effort. Exercise continued until decompression. V-5) 160 min prebreathe with 140 min of ILE - first 40 min at 14.7 psi, then 30 min at 10.2 psi (breathing 26.5% oxygen) after a 20 min depress, simulating a suit donning period. Subjects were then repressed to 14.7 psi and performed another 50 min of lower body ILE, followed by 50 min rest before decompression. The V-4 protocol was rejected with 3 DCS/6 person-exposures. Initial V-5 testing has produced 0 DCS/11 person-exposures (ongoing trials). The difference in DCS rate was significant (Fisher Exact p=0.029). The observations of DCS were significantly lower in early V-5 trials than in V-4 trials. Additional studies are required to evaluate the relative contribution of the variables in exercise distribution, the 10.2 psi depress/repress component, pre-decompression rest, or possible variation in total oxygen consumption
Particle acceleration during merging-compression plasma start-up in the Mega Amp Spherical Tokamak
Magnetic reconnection occurred during merging-compression plasma start-up in the Mega Amp Spherical Tokamak (MAST), resulting in the prompt acceleration of substantial numbers of ions and electrons to highly suprathermal energies. Accelerated field-aligned ions (deuterons and protons) were detected using a neutral particle analyser at energies up to about 20 keV during merging in early MAST pulses, while nonthermal electrons have been detected indirectly in more recent pulses through microwave bursts. However no increase in soft X-ray emission was observed until later in the merging phase, by which time strong electron heating had been detected through Thomson scattering measurements. A test-particle code CUEBIT is used to model ion acceleration in the presence of an inductive toroidal electric field with a prescribed spatial profile and temporal evolution based on Hall-MHD simulations of the merging process. The simulations yield particle distributions with properties similar to those observed experimentally, including strong field alignment of the fast ions and the acceleration of protons to higher energies than deuterons. Particle-in-cell modelling of a plasma containing a dilute field-aligned suprathermal electron component suggests that at least some of the microwave bursts can be attributed to the anomalous Doppler instability driven by anisotropic fast electrons, which do not produce measurable enhancements in soft X-ray emission either because they are insufficiently energetic or because the nonthermal bremsstrahlung emissivity during this phase of the pulse is below the detection threshold. There is no evidence of runaway electron acceleration during merging, possibly due to the presence of three-dimensional field perturbations
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