771 research outputs found
Utility of correlation techniques in gravity and magnetic interpretation
Internal correspondence uses Poisson's Theorem in a moving-window linear regression analysis between the anomalous first vertical derivative of gravity and total magnetic field reduced to the pole. The regression parameters provide critical information on source characteristics. The correlation coefficient indicates the strength of the relation between magnetics and gravity. Slope value gives delta j/delta sigma estimates of the anomalous source. The intercept furnishes information on anomaly interference. Cluster analysis consists of the classification of subsets of data into groups of similarity based on correlation of selected characteristics of the anomalies. Model studies are used to illustrate implementation and interpretation procedures of these methods, particularly internal correspondence. Analysis of the results of applying these methods to data from the midcontinent and a transcontinental profile shows they can be useful in identifying crustal provinces, providing information on horizontal and vertical variations of physical properties over province size zones, validating long wavelength anomalies, and isolating geomagnetic field removal problems
Utility of correlation techniques in gravity and magnetic interpretation
Two methods of quantitative combined analysis, internal correspondence and clustering, are presented. Model studies are used to illustrate implementation and interpretation procedures of these methods, particularly internal correspondence. Analysis of the results of applying these methods to data from the midcontinent and a transcontinental profile show they can be useful in identifying crustal provinces, providing information on horizontal and vertical variations of physical properties over province size zones, validating long wave-length anomalies, and isolating geomagnetic field removal problems. Thus, these techniques are useful in considering regional data acquired by satellites
THE UNSTABLE SPECIES AND THE ISOTOPE EFFECT IN THE PYROLYSIS OF DIBORANE IN A SHOCK TUBE
From American Chemical Society 145th National Meeting, New York, Sept. 1963. The pyrolysis of diborane was examined using a chemical shock tube as a reactor. Additional evidence for the existence of hexaborane-12 and heptaborane- 11 and -13 was obtained. The presence of a large net normal isotope effect in the formation of tetraborane and hexaborane and a net inverse isotope effect in the formation of pentaborane-9 are observed. A mechanism, consisting of a series of competitive reactions and eqailibria, in which tetraboraue is the precursor of pentaborane-11 and hexaborane but not of pentaborane-9 is shown to be compatible with the observed isotope effect. Data obtained by examining the pyrolysis of various mixtures of boron hydrides are also consistent with the mechanism. (auth
Educational recommendations for the conduct, content and format of EULAR musculoskeletal ultrasound Teaching the Teachers Courses
To produce educational guidelines for the conduct, content and format of theoretical and practical teaching at EULAR musculoskeletal ultrasound (MSUS) Teaching the Teachers (TTT) Courses
Error threshold in optimal coding, numerical criteria and classes of universalities for complexity
The free energy of the Random Energy Model at the transition point between
ferromagnetic and spin glass phases is calculated. At this point, equivalent to
the decoding error threshold in optimal codes, free energy has finite size
corrections proportional to the square root of the number of degrees. The
response of the magnetization to the ferromagnetic couplings is maximal at the
values of magnetization equal to half. We give several criteria of complexity
and define different universality classes. According to our classification, at
the lowest class of complexity are random graph, Markov Models and Hidden
Markov Models. At the next level is Sherrington-Kirkpatrick spin glass,
connected with neuron-network models. On a higher level are critical theories,
spin glass phase of Random Energy Model, percolation, self organized
criticality (SOC). The top level class involves HOT design, error threshold in
optimal coding, language, and, maybe, financial market. Alive systems are also
related with the last class. A concept of anti-resonance is suggested for the
complex systems.Comment: 17 page
The Nature of the Near-IR Core Source in 3C 433
We report the analysis of near-infrared imaging, polarimetric and
spectroscopic observations of the powerful radio galaxy 3C433, obtained with
the HST and UKIRT telescopes. The high spatial resolution of HST allows us to
study the near-nuclear regions of the galaxy (<1 kpc). In line with previous
observations, we find that 3C433 has an unresolved core source that is detected
in all near-IR bands, but dominates over the host galaxy emission at 2.05 um.
Our analysis reveals: (1) the presence of a dust lane aligned close to
perpendicular (PA=70\pm5\degr) to the inner radio jet axis
(PA=-12\pm2\degr); (2) a steep slope to the near-IR SED (;
F); (3) an apparent lack of broad permitted
emission lines at near-IR wavelengths, in particular the absence of a broad
Pa emission line; and (4) high intrinsic polarization for the
unresolved core nuclear source ( per cent), with an E-vector
perpendicular (PA=83.0\pm 2.3\degr) to the inner radio jet. Using five
independent techniques we determine an extinction to the compact core source in
the range 3<A_V<67 mag. An analysis of the long wavelength SED rules out a
synchrotron origin for the high near-IR polarization of the compact core
source. Therefore, scattering and dichroic extinction are plausible polarizing
mechanisms, although in both of these cases the broad permitted lines from the
AGN are required to have a width >10^4 km/s (FWHM) to escape detection in our
near-IR spectrum. Dichroic extinction is the most likely polarization mechanism
because it is consistent with the various available extinction estimates. In
this case, a highly ordered, coherent toroidal magnetic field must be present
in the obscuring structure close to the nucleus.Comment: 12 pages, 5 figures, accepted for publication in MNRA
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