True polarization curves for Beta Lyrae.
Beta Lyrae intrinsic polarization amount and phase dependence in visual, blue and UV light observed, analyzing polarization curves
ECLIPSING BINARY STAR↗
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Results for “Polarization curve”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The polarization curve and the absolute diameter of Vesta
Photoelectric polarization curve, reflectivity and absolute diameter of Vesta, comparing with Lyot curve
Veverka, J.↗
Analytical methods for computing the polar curves of airplanes
This report presents a method of calculating polar curves which is at least as precise as graphical methods, but it more rapid. Knowing the wind tunnel test of a wing and the performances of an airplane of the same profile, it is easy to verify the characteristic coefficients and, at the same time, the methods determining induced resistances.
LE SUEUR↗
Observations of structure in the interstellar polarization curve Preliminary results
We have measured the wavelength dependence of the interstellar polarization curve with higher wavelength resolution than has generally been used before. Our data show structure which has been previously unknown, and which may have important implications with respect to the composition of the interstellar grains. It is similar in general form to structure predicted on the basis of a theoretical model designed by us to give a detailed match to the extinction structure.
Mavko, G. E.↗
Asteroid reflectivities from polarization curves - Calibration of the 'slope-albedo' relationship.
The relationship between h, the slope of the positive branch of a polarization curve, and A, the normal reflectance of the surface, has been calibrated using a wide range of published data. It is determined that asteroid albedos can be inferred meaningfully by this method without prior knowledge of the detailed mineralogical composition of asteroid surfaces.
Veverka, J.↗
Interpretation of the brightness and polarization curves of the moon
Theoretical models for lunar brightness at small phase angles and polarization of moonlight
POLARIZATION↗
New Method of Determining the Polar Curve of an Airplane in Flight
A fundamental defect of existing methods for the determination of the polar of an airplane in flight is the impossibility of obtaining the thrust or the resistance of the propeller for any type airplane with any type engine. The new method is based on the premise that for zero propeller thrust the mean angle of attack of the blade is approximately the same for all propellers if this angle is reckoned from the aerodynamic chord of the profile section. This angle was determined from flight tests. Knowing the mean angle of the blade setting the angle of attack of the propeller blade at zero thrust can be found and the propeller speed in gliding obtained. The experimental check of the new method carried out on several airplanes gave positive results. The basic assumptions for the construction of the polars and the method of analyzing the flight data are given.
Yegorov, B. N.↗
Stress Corrosion Cracking of titanium alloys - Electrochemical kinetics, SCC studies with Ti-8-1-1, SCC and polarization curves in molten salts, liquid metal embrittlement, and SCC studies with other titanium alloys Quarterly progress report, period ending 31 Dec. 1969
Stress corrosion cracking behavior in titanium, molybdenum, and aluminum alloys, and electrochemical kinetic studies
Beck, T. R.↗
The logarithmic polar curve-it's theory and application to the predetermination of airplane performance
The logarithmic polar curve has for several years been used by the most prominent aerodynamical laboratories as well as by airplane manufacturers in Europe. To show more clearly the practical application of the polar curve, a series of examples are given with suggestions for solution. After a discussion of the theory and the practical application of the polar curve, the following problems are discussed: climbing flight, speed at various altitudes, and the characteristics of two seater observation airplanes of recent design.
Cronstedt, Val↗
Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings
This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.
Coatings↗
Understanding the E balance for water management in hydroxide exchange membrane fuel cells
As a key challenge for hydroxide exchange membrane fuel cells (HEMFCs), understanding water management deeply is critical for performance and durability improvement. Here, in this work, we show that the balance between water generation and phase-change-induced (PCI) flow is the main factor controlling cell voltage over a wide range of conditions where the cells are vulnerable to severe flooding. The regulation of flooding by heat generation can be reflected by a stable voltage with increase of current density in the polarization curve. This PCI balance voltage (E balance ), which determines the shape of polarization curve, is modeled as a function of cell operating conditions and gas diffusion layer (GDL) properties. Temperature, pressure, and thermal conductivity of GDL were found important for tuning the level of E balance , both in HEMFCs and proton exchange membrane fuel cells. The understanding of E balance will help to generate strategies for resolving flooding in HEMFCs, and it offers a new perspective for polarization curve interpretation.
25 ENERGY STORAGE↗
A study of the asymmetric wind of P Cygni
Results of optical linear spectropolarimetric measurements of the hypergiant P Cygni are presented. The data indicate that both the intrinsic polarization and the position angle vary with time. It is found that, prior to removing the interstellar polarization vector, the polarization varies by 0.642 percent, while the position angle takes on values between 27.0 and 39.8 deg. The wavelength dependence of the polarization curve also changes with time, indicating that the intrinsic polarization curve is not always constant with the wavelength. After a model is determined for interstellar polarization, it is found that the amplitude of the intrinsic polarization of P Cyg varies from 0.04 to 0.48 percent, with a change of 0.12 percent on successive nights. It is inferred from this large variation in the polarization on such a short timescale that the scattering material lies close to the star. Several possible geometries to describe the circumstellar material of P Cygni are presented.
Taylor, M.↗
Exploring the Impacts of Conditioning on Proton Exchange Membrane Electrolyzers by In Situ Visualization and Electrochemistry Characterization
For a proton exchange membrane electrolyzer cell (PEMEC), conditioning is an essential process to enhance its performance, reproducibility, and economic efficiency. To get more insights into conditioning, a PEMEC with Ir-coated gas diffusion electrode (IrGDE) was investigated by electrochemistry and in situ visualization characterization techniques. The changes of polarization curves, electrochemical impedance spectra (EIS), and bubble dynamics before and after conditioning are analyzed. The polarization curves show that the cell efficiency increased by 9.15% at 0.4 A/cm 2 , and the EIS and Tafel slope results indicate that both the ohmic and activation overpotential losses decrease after conditioning. The visualization of bubble formation unveils that the number of bubble sites increased greatly from 14 to 29 per pore after conditioning, at the same voltage of 1.6 V. Under the same current density of 0.2 A/cm 2 ; the average bubble detachment size decreased obviously from 35 to 25 µm. Furthermore, the electrochemistry and visualization characterization results jointly unveiled the increase of reaction sites and the surface oxidation on the IrGDE during conditioning, which provides more insights into the conditioning and benefits for the future GDE design and optimization.
08 HYDROGEN↗
Wing resistance near the ground
In the present treatise, a convenient method will be indicated, which makes it possible to determine the polar curve of an airplane at short distances from the ground by a simple short calculation, when the polar curve is known for flight in unlimited space.
GROUND EFFECT↗
Electrochemical approach for passivating steel and other metals and for the simultaneous production of a biocide to render water potable
Potentiostatic polarization curves indicated that the cathodic reactions in deaerated KI-I2 water solutions were due to iodine reduction and hydrogen evolution. In the presence of oxygen an additional reduction wave appeared. Anodic polarization curves revealed that iodine could be produced in the region of potential from +600 to +1000 nv vs. SCE.
Source record↗
Polarimetric observations of 9 Metis, 15 Eunomia, 89 Julia, and other asteroids.
White-light polarization curves for a number of asteorids are presented. All have well-developed negative branches, suggestive of relatively dark, texturally complex surfaces - possibly regoliths. Geometric albedos, estimated from the positive branch of the polarization curves, show that a significant dispersion in surface albedo exists within the asteroid belt.
Veverka, J.↗
Photopolarimetric observations of the minor planet Flora.
Review of the rotation period, phase coefficients, and polarization curve of the unusual asteroid Flora. It is an almost spherical asteroid whose period of rotation is probably 13.6 h, but may be only one half of this. Its surface layer consists of a dark material resembling lunar surface soil, but since the polarization curves of Flora and the moon, though generally similar, are not identical the surface of Flora must differ somewhat either in composition or in texture from that of the moon.
Veverka, J.↗
Minor planets and related objects. IX - Photometry and polarimetry of /1685/ Toro.
UBV photometry, lightcurves, a polarization-phase relation, and rotational polarization curves of Toro were obtained, June-August 1972. The average colors are B-V = 0.87 and U-B = 0.47 mag, showing some reddening with phase. The geometric albedo of Toro in the B filter is 0.14 which corresponds to an effective mean radius of 2.2 km plus or minus 0.4 (p.e.). The rotational polarization curves indicate that the lightcurves are mostly due to shape, but some albedo variation over the surface is detected as well. The shape is elongated, and probably irregular, with a cross-sectional area ratio of about 3.2, the maximum effective radius is 2.8 km and the minimum, 1.6 km.
Dunlap, J. L.↗