Search results for " petrology"

Collocated measurements of boundary layer cloud microphysical and radiative properties: A feasibility study

2010

[1] First data from collocated, helicopter-based measurements of boundary layer cloud microphysical properties (effective droplet radius Reff, droplet number concentration N) and spectral radiative quantities (cloud optical thickness τ, cloud top albedo ρ, reflectivity ) are presented. The in situ measurements of the microphysical cloud properties were collected by the Airborne Cloud Turbulence Observation System (ACTOS) attached to a helicopter by a 145 m long rope. Cloud spectral reflectivity was derived from radiances measured by grating spectrometers combined with downward looking optical inlets installed underneath the helicopter. Correlations between cloud microphysics and reflected r…

Reply to comment by R. Grard et al. on “An analysis of VLF electric field spectra measured in Titan's atmosphere by the Huygens probe”

2011

Messungen der Himmelsstrahlung und deren Polarisationsgrad während der Sonnenfinsternis am 15.2.1961 in Viareggio (Italien)

1961

On the occasion of the total solar eclipse in Viareggio (Italy) measurements of intensity of sky radiation and polarization have been carried out at 90 degrees vertical distance from the sun. UV-, green- and red-filters have been used. The results showed a diminution of the intensity during the eclipse of about 3 powers of ten. The sky brightness in the point 90 degrees distant during the total eclipse was similar to the brightness when sun is 7 degrees below the horizon. About one minute before the total eclipse the degree of polarization diminuished to zero. — Furthermore photos of nearly the total sky were made using two cameras with wide angle lenses.

Digital rock physics, chemistry, and biology: challenges and prospects of pore-scale modelling approach

2021

Abstract Conventional and unconventional hydrocarbon rocks have complicated pore structures with heterogeneities distributed over various length scales (from nanometre to centimetre or even larger scales). Effective characterization of the properties of such rocks based on their digital twins is a challenging task. Digital rock physics (DRP) can be used to quantify the structural and morphological parameters of rocks directly and predict flow transport properties at the pore scale. Digital rock chemistry (DRC) or biology (DRB) applies when the changes in pore structures are due to interaction with solutes or microbial activities. Fluid–rock interactions or microbial activities complicate fl…

Determination of Reference Values for NIST SRM 610-617 Glasses Following ISO Guidelines

2011

We present new reference values for the NIST SRM 610–617 glasses following ISO guidelines and the International Association of Geoanalysts’ protocol. Uncertainties at the 95% confidence level (CL) have been determined for bulk- and micro-analytical purposes. In contrast to former compilation procedures, this approach delivers data that consider present-day requirements of data quality. New analytical data and the nearly complete data set of the GeoReM database were used for this study. Data quality was checked by the application of the Horwitz function and by a careful investigation of analytical procedures. We have determined quantitatively possible element inhomogeneities using different …

Instabilities in a staircase stratified shear flow

2017

We study stratified shear flow instability where the density profile takes the form of a staircase of interfaces separating uniform layers. Internal gravity waves riding on density interfaces can r...

THEORETISCHE UNTERSUCHUNG UBER DIE MEHRFACHAUFSTELLUNG VON GEOPHONEN*

1958

The receiving of seismic waves by multiple geophones (geophone-group) is described by a system of coupled differential equations considering only effective resistances. For so-called symmetrical connections of the geophone-group which are used in practice nearly in all cases, a method can be given for solving this system of differential equations. The solutions so derived are valid for seismic waves of any shape. The calculation takes into account the coupling of the geophones as well as the building-up transient oscillations. A suitable measure of superposition is defined, based on the energy transferred during the receiving of the seismic waves. By this means effects similar to interferen…

THE QUANTITATIVE RECORDING OF SEISMIC EVENTS WITH EXTREMELY LARGE AMPLITUDE VARIATIONS BY DISCONTINUOUS GAIN CONTROL*

1963

A transistorized combination of multivibrators is described, by which the gain is set according to a time programme. This equipment allows quantitative recording of seismic events with extremely large amplitude variations. Some possible applications of this recording system to seismic research are discussed. ZUSAMMENFASSUNG Es wird eine transistorisierte Zeitschalterkombination beschrieben, die zur Einstellung vorgewahlter Verstarkungsstufen nach Zeitprogramm dient. Mit dieser Anordnung lassen sich seismische Vorgange mit beliebigen Amplituden-Anderungen quantitativ erfassen. Es werden einige Beispiele der seismischen Forschung diskutiert, bei denen diese Regis-triertechnik erfolgreich eing…

<i>Editorial Note</i>A case of plagiarism: "Modelling of the wave fields by the modification of the matrix metho…

2014

Solar radiation extinction, sky radiation, sky light polarization and aerosol particle total number and size distribution on the Island Maui (Hawaii)

1968

During April 1964 and from August through September 1965 measurements have been performed on the Maui Island, Hawaii. The results can be summarized as follows: a) the spectral extinction coefficient has a diurnal variation. The greatest value is found during noon. Its wavelength dependency shows an ‘anomalous extinction’, the maximum of extinction is to be found at 0.55 μ (Figures 1–3). b) the spectral radiance distribution of the total sky indicates the tendency that the aerosol size distribution does not follow a continuous power law. The exponent for small particles seems to bev*1 μ (Figure 8). d) the distribution of spectral degree of sky light polarization shows two maxima of polarizat…