294 research outputs found
Test results of the DOE/Sandia 17 meter VAWT
A review is given of the test program of a 17 meter Vertical Axis Wind Turbine VAWT. Performance test results are discussed including difficulties encountered during the VAWT operation along with ways of solving these problems
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Symmetry Breaking and the Inverse Energy Cascade in a Plasma
The application of electrostatic bias to both low density plasma with coherent fluctuations and high density plasma with turbulent fluctuations confined by a magnetic dipole are investigated. Previously, electrostatic biasing of low density plasma was symmetric, drove rapid plasma rotation, and excited the centrifugal interchange instability.
This research investigates the application of non-symmetric bias and the influence of broken symmetry on strongly turbulent plasmas. Non-symmetric bias is applied through either point biasing or an equatorial array spanning the device. In both cases, the spatial symmetry of applied bias dramatically effects the plasma fluctuations. With bias applied, the plasma achieves a new equilibrium characterized by amplified low order modes and diminished amplitude of higher order modes.
Although the turbulent spectrum changes, the RMS fluctuation level is unchanged by the bias. Bias also causes the turbulent electrostatic fluctuations to coalesce into a quasi-coherent mode and the appearance of increased coherence. The effect of bias configuration is also seen to change the measured levels of nonlinear coupling. Non-symmetric biasing increases nonlinear coupling while symmetric biasing leaves the coupling unchanged. These results represent the first experimental demonstration of symmetry breaking driving the inverse energy cascade in a quasi-two dimensional plasma system. The application of dynamic and rotating electrostatic bias as well as plans for applying turbulent feedback are discussed
Section 253 of the Telecommunications Act of 1996: A Permanent Physical Appropriation of Private Property that Must Be Justly Compensated
Section 253 of the Telecommunications Act of 1996 was promulgated in an effort to remove unnecessary regulation by local governments and open up competition among local phone companies, cable providers, and other telecommunications concerns. However, this provision effectively prohibits local governments from managing their rights-of-way. Furthermore, it violates modern Fifth Amendment takings jurisprudence, Section 253 and the first three FCC and court decisions examining it not only have jeopardized effective municipal management and resource allocation discretion, but also have usurped local governments\u27 property rights without just compensation in explicit violation of the United States Constitution
Section 253 of the Telecommunications Act of 1996: A Permanent Physical Appropriation of Private Property that Must Be Justly Compensated
Section 253 of the Telecommunications Act of 1996 was promulgated in an effort to remove unnecessary regulation by local governments and open up competition among local phone companies, cable providers, and other telecommunications concerns. However, this provision effectively prohibits local governments from managing their rights-of-way. Furthermore, it violates modern Fifth Amendment takings jurisprudence, Section 253 and the first three FCC and court decisions examining it not only have jeopardized effective municipal management and resource allocation discretion, but also have usurped local governments\u27 property rights without just compensation in explicit violation of the United States Constitution
Basic design of MOSFET, four-phase, digital integrated circuits
MOSFET is defined as metal oxide semiconductor field-effect transistor. The integrated circuit design relates strictly to logic and switching circuits rather than linear circuits. The design of MOS circuits is primarily one of charge and discharge of stray capacitance through MOSFETS used as switches and active loads. To better take advantage of the possibilities of MOS technology, four-phase (4[phi]) circuitry is developed. It offers higher speeds and lower power while permitting higher circuit density than does static or two-phase (2[phi]) logic. Equations are developed that apply directly to the design of four-phase logic along with examples of circuitry that show their use. The most unique of these is the equation for discharge through two or more MOSFETS in series from a saturated condition. the effects of stray capacitance on circuit performance are explained. Methods for overcoming deleterious effects and taking advantage of helpful effects are discussed and solved. The main effect is that of discharge of the stored charge on a logic node through the gate to source overlap capacitance when a phase clock returns to ground. In all, a complete method for designing 4[phi] circuitry is developed and explained in appropriate examples --Abstract, page i
Mechanisms of nitrogen heterocycle influence on turbine fuel stability
Lewis bases were extracted from a Utah COED syncrude via ligand exchange. Addition of this extract to Jet A at levels as low as 5 ppm N produced deterioration of stability in both JFTOT and accelerated storage tests (7 days at 394 K with 13:1air to fuel ratio). Comparable effects on Jet A stability were obtained by addition of pyridine and quinoline, while pyrrole and indole were less detrimental at the same concentration level. The weight of deposit produced accelerated storage tests was found to be proportional to the concentration of added nitrogen compound. Over the narrow temperature range accessible with the experimental method, Arrhenius plots obtained by assuming specific rate to be proportional to the weight of material deposited in seven days exhibit greater slopes in the presence of those nitrogen compounds producing the greater deposition rates. It is shown that despite variation in appearance the elemental composition and spectral characteristics of the deposits are unaffected by addition of the nitrogen compounds. The linearity of the Arrhenius plots and of a plot of Arrhenius slope versus intercept for all the compounds suggests a constancy of mechanism over the range of temperature and heterocycles studied
Discussion: Flow Measurements with Fluorescent Tracers
Stream discharge measurements with chemical dilution techniques have
been proposed in several forms since the beginning of this century (Groat).
Early techniques consisted of introducing a chemical, usually brine, at a
known rate into flowing water and determining the resulting concentration
of the chemical in the stream at a section far enough downstream to assure
adequate mixing of the chemical with the water. A variation of this method,
and the technique used in the present study, was described by Barbagelata
in 1928. In that method, a known quantity of tracer was added, as a slug, to
the stream to be measured. At a sampling station sufficiently far downstream
for adequate lateral mixing, the tracer concentration-time curve was determined.
The stream discharge was then calculated from the amount of
tracer added and the area measured under the curve
An Experimental Buried Multiset Irrigation System
CRITERIA for the design, construction,
and operation of an
experimental buried lateral, gravity
multiset irrigation system are presented.
The system operating without
automatic controls has a potential
water application efficiency of 80 percent
with very little runoff or erosion.
With automatic controls and with
water available on demand, light,
frequent irrigations can be applied
with 90 to 95 percent efficiencies.
The energy required to operate the
system is minimal and only periodic
inspection and maintenance services
are required of the operator. Estimated
cost and benefits indicate that
this system may be economically feasible,
practical, and attractive with
increasing energy costs and labor
shortages
A Scintillating Fiber Hodoscope for a Bremstrahlung Luminosity Monitor at an ElectronPositron Collider
The performance of a scintillating fiber (2mm diameter) position sensitive
detector ( cm active area) for the single bremstrahlung
luminosity monitor at the VEPP-2M electron-positron collider in Novosibirsk,
Russia is described. Custom electronics is triggered by coincident hits in the
X and Y planes of 24 fibers each, and reduces 64 PMT signals to a 10 bit (X,Y)
address. Hits are accumulated (10 kHz) in memory and display (few Hz) the
VEPP-2M collision vertex. Fitting the strongly peaked distribution ( 3-4
mm at 1.6m from the collision vertex of VEPP-2M ) to the expected QED angular
distribution yields a background in agreement with an independent determination
of the VEPP-2M luminosity.Comment: LaTeX with REVTeX style and options: multicol,aps. 8 pages,
postscript figures separate from text. Accepted in Review of Scientific
Instruments (~ Aug 1996
Comparative physiological reactions of European and Indian cattle to changing temperature
"January, 1953.
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