Die ≪Strahlung≫ bei Pouillet und Kirchhoff

Zusammenfassung Der Widerspruch zwischen den Strahlungsgesetzen der Physik und der Definition der Strahlung durchPouillet, die allen bisherigen Strahlungs-Messungen zu Grunde liegt, wird am Modell des schwarzstrahlenden Hohlraums vonKirchhoff gezeigt. Auch die Bestimmungen der Solarkonstante (Kalitins's Liste) sind verloren.

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Summary The contradiction ofPouillet's radiation and the physical laws of radiation sinceKirchhoff, Boltzmann-Stefan, Wien, Lummer andKurlbaum is by the model of the black radiating body ofKirchhoff demonstrated. The measurements of radiation have followed til now to the antiquated idea ofPouillet. The determination of the solar constant as inKalitin's list represented also is lost.

     

Turbidometric estimations in Mexico city using the Volz sun photometer

Summary Measuring, with the aid of two filters, the instantaneous intensity of the solar radiation in two wave lengths ( _B = 0.44 , _R = 0.64 ) by means of a sun photometer designed byVolz, we carried out determinations of the decadic turbidity coefficientB (=0.5 ) and the wave length exponent of the haze extinction for Mexico City. Observations were made for almost two and a half years (1960 to 1962 period). A seasonal size distribution in both parameters was found. Although the data thus obtained are provenient of a contaminated atmosphere, comparison of our data is made with those found for higher latitudes ofÅngström, Schüepp andVolz. The height of the homogeneous haze layerH _D was calculated showing pronounced variations for a given wind direction. The maximum and minimum values ofB enable us to get, by the first approximation, the aerosol size distribution ofJunge for our latitudes. However, for exceptional very clear days having maximum actinometric intensity of the solar radiation the sensitivity of the microamperimeter in theVolz sun photometer fails.     

Zur Analyse der Genauigkeit von mehrmals mit einer Gravimetergruppe gemessenen gravimetrischen Verbindungen

Summary In order to evaluate the accuracy of measurements repeated by a set of gravimeters the semi-systematic errors ₂ and ₃ were introduced besides the random error ₁ in[1]. It is shown that Eqs.(10) and(11), given in[1], should not be used to determine these errors, but Eqs.(8) and(9).     

Die Seismizität der Türkei

Summary Using the fromulae given byGutenberg andRichter, the writer has computed the magnitude and energy of 1804 earthquakes which occurred in Turkey during the period 1850–1960. For drawing the Isenerget, the formula =log₁₀ S has been used in accordance with the definitions given byToperczer andTrapp, whereS=e _i/F·p represents the energy in erg/m² h corresponding to the surface element of 0.5° Lat. x 0.5° Long. Also the relationship between the seismicity and the tectonics of Turkey has been studied by drawing the maps of the epicenters, the focus-depths and the frequences of the earthquakes with various intensities.     

Studies on night radiation at some Indian Stations

Summary The present paper contains studies of the nocturnal radiation at some Indian Stations (Madras, Waltair, Nagpur, New Delhi and Poona) with the help of the Ångström compensation Pyrgeometer. The technique of measurement is also described briefly. A study of the mean monthly variation of sky radiation during clear as well as all nights has been discussed. A comparitive study of mean monthly values of sky and other nocturnal radiation components at these stations is also presented. Ångström, [4]²) expressed the dependence of sky radiationS—on water vapour pressuree (mm of mercury) at the earth's surface and air temperatureT (degrees absolute), near the instrument to be given byS=T ⁴ (0.75–0.32×10^–0.069e ) cal/cm²/min. According to this semi-empirical relationship, the calculated values of sky radiation for clear nights are smaller than the observed values of sky radiation at all the above stations. It is for this reason the authors obtained a new formula with different constants using nine years observed data at all the stations. To investigate the value of the constant, the mean annual observations presented for nine years from clear skies were analysed for correlations betweenB (black body radiation) versesS (sky radiation),N (net radiation) andE (absolute error) and obtained a good correlation co-efficients 0.90, 1 and 0.98 respectively. The new suggested formula isS=T ⁴ (0.88–0.32×10^–0.069e ) cal/cm²/min, 267° A<T<313° A. It is also verified using with observed data of different years of the stations. The agreement between the computed values with the new formula of sky radiation and observed sky radiation is found to be good.     

Velocity changes associated with generalized triaxial deformation of pyrophyllite

Compressional and shear-wave velocities (V _p andV _s ) were measured during the generalized triaxial deformation (i.e. _{1 2}=2 ₃) of pyrophyllite. Observed velocity changes could be ascribed to crack development during dilatancy. Velocity changes were very localized with respect to the ultimate failure plane. The orientation and development of the failure plane was continuously observed with laser holography. Velocity reverals, i.e. changes from a decreasing trend to an increasing trend, were documented in a wet sample in bothV _p andV _s . These changes in bothV _p andV _p are inconsistent with dialatancy-diffusion models. The reversals were interpreted as a reflection of local stress reorientation caused by a slowly propagating fault.     

Mass transport in rotatory tidal currents

Summary A perturbation method is used to calculate steady non-linear effects in rotatory tidal currents. The inclusion of the Coriolis acceleration leads to a uniquely determined second order current system in the tidal stream. This is shown to be absent in high frequency gravity waves. It is found that particle drift, or mass transport, is critically dependent on this mean current, and consequently on the value off/,f being the Coriolis parameter, and the angular frequency of the oscillation.     

Depression in the low-latitude horizontal intensity due to quiet-time ring current

Summary The external field due to plasma within the magnetosphere has been computed as a function ofA _p, which is a measure of solar wind velocity, for very quiet to slightly disturbed conditions using mean daily horizontal intensity from 1932 to 1968 at Alibag. The intensity, corrected for secular change and reduced to a common epoch, showed initially a small increase withA _p followed by a steady depression with further increase in the index. ForA _p7.5, which is representative of conditions over the 33-hour interval during which data relating to low-energy protons were acquired and used byHoffman andBracken [4]²) to compute current distributions, the decrease, computed here from surface data, is 6 . This is in goodagreement with the southward directed field of the quiet-time proton belt 9±5 obtained byHoffman andBracken.     

Analysis of State of Stress During The 1997 Earthquake Swarm In Western Bohemia

Focal mechanisms of 70 events of the January 1997 earthquake swarm were analysed using the Gephart and Forsyth method to determine the state of stress in the West Bohemia/Vogtland region and to reveal possible stress variations during the swarm activity. The method was applied to the whole set of 70 focal mechanisms and to several subsets distinguishing magnitudes of events and the spatial and temporal distribution of the swarm. The three representative stress models A ( ₁ ,A: 0/45 (az/dip), ₂ A: 134/35, ₃ A: 243/25), B ( ₁ ,B: 162/38, ₂ B: 263/14, ₃ B: 10/49), and C ( ₁ C: 135/30, ₂ C: 1/50, ₃ C: 239/23) which could characterise the state of stress in the region were found. Model C can be considered to be the most probable stress model because of its consistency with the European stress field. The results of the stress analysis applied to the individual subsets of focal mechanisms indicate that the state of stress was more uniform during the first phase of the swarm. To distinguish between the fault plane and the auxiliary plane of fault plane solutions a statistical approach was used. The results showed that the fault planes striking NW-SE and dipping 45° to NE were activated during the swarm.     

Variation of certain parameters of regional stress tensor under condition of rockburst hazard

The feasibility of gaining valuable geomechanical information derived from seismological data and its specialist interpretation for utilisation in the area of assessing hazards due to mining tremors and rockbursts has become a development of signal importance in mining seismology. Undoubtedly of particular interest is a certain knowledge of the directions of the principal stresses ₁, ₂, ₃ of the regional stress tensor. For their determination, use is made of a set of parameters from the mining tremors' regional focal mechanism solutions (angular parameters of nodal planes and axes of principal stresses in the tremor focus —P andT). Results of research conducted at the Szombierki and Wujek mines and analysis of calculated results for parameters of regional stress tensor show that there exist appreciable differences between values of these parameters and also a clear correlation with local extraction conditions that is of significance from the point of view of seismic hazard.     

Estimation of long wave radiation by an empirical method

Summary Utilising two years data collected at two tropical coastal stations, Madras (13°04N, 80°15E) and Waltair (17°42N, 83°18E) and for one tropical continental station, Nagpur (21°09N, 79°07E), the authors have re-evaluated the constants ofBrunt's regression equation. Analyses of the observations for Waltair and Nagpur show good correlation coefficients (r) between the values of the effective emissivity of the atmosphere (the effective emissivity is the ratio of incoming long-wave sky radiation at the surfaceR _s , to black body radiation T ⁴) and the square root values of surface vapour pressuree (mb). The value ofr for Waltair from radiometer observations is 0.98. It is also determined for Waltair and Nagpur from Ångström compensation pyrgeometer observations as 0.83 and 0.91 respectively. A low correlation co-efficient 0.56 is obtained for Madras. It might be due to higher surface vapour pressure values at Madras than at Waltair and Nagpur. The applicability of the reduced regression equations are examined for different years for the different stations. The agreement between the computed values with the new regression equations and the observed long-wave sky radiation at the surface seems to be quite good.     

P in the shadow zone of the earth's core—Part I

Summary Regional variations have been indicated in the slope of theP travel-time curve in the shadow zone of the earth's core. Further study is needed since the uncertainties of the slope are large, especially for the observations from North American stations. There is no significant difference between themean slope of theP travel-time curve in the 95°102.9 range and those obtained byJeffreys, andJeffreys andBullen. However, there is a significant difference between themean slope in the 103° to 135° range as obtained in this study, and those obtained byJeffreys andBullen, and in a later revision byJeffreys. Themean travel-time curve ofP in the shadow zone of the earth's core should be lowered. A trial travel-time table is given with amean slope of 4.41 sec/deg. This table is in close agreement with the times obtained byGutenberg andRichter, and with the trial travel-times ofLehmann. Under the assumption of diffraction the longitudinal wave velocity has been determined to be 13.7 km/sec at the core-mantle boundary.This paper was presented at the Annual Meeting of the Seismological Society of America Reno, Nevada, 1966.     

Complexities of rock fracture and rock friction from deformation of Westerly granite

A series of rock friction experiments has been carried out to study the complexities in rock fracture and rock friction. Intact Westerly granite samples were loaded to shear failure in a laboratory polyaxial loading apparatus. The resultant fractured samples were reloaded to cause frictional sliding. Both polyaxial loading (₁ > ₂ > ₃ > 0) and equal confining condition (₁ > ₂ = ₃ > 0) were used. The deformation processes were monitored by macroscopic axial stress-strain, optical holography, and ultrasonic velocity measurements.Intense localized deformation along the fracture occurred very early in the loading of fractured samples. Contacts on the fracture surfaces continuously broke during loading. No acoustic velocity anomaly was observed for the fractured sample, in contrast to a 25% drop in the velocity before the failure of the corresponding intact sample. The current study and previous research suggest that the deformation localization is an important process in governing the instability of rock friction. Instability analysis of rock friction needs to include not only the deformation processes along the sliding surfaces, but also those adjacent to the fractures such as the localized deformation along the fractures observed in the current study. The instability analysis of rock friction with rate- and state-dependent friction laws does not specifically include the deformation localization adjacent to the faults and thus ignores an important class of instability as described byRudnicki (1977).A dependence of frictional strengths on the stress components normal to the sliding and in the plane of the fracture surface was observed. This dependence can be understood by considering the loading of the irregular fracture surface under polyaxial loading conditions. This observation requires the friction laws in the macroscopic scale to be modified for those cases where the three principal stresses (₁, ₂, and ₃) are significantly different.     

Changes of electric conductivity in the neighbourhood of the curie temperature of basalts

Summary In investigating the electric conductivity of rocks as a function of the temperature it was found that rocks containing ferrimagnetic minerals display a change in the slope of the functionlg =f(1/T) in the neighbourhood of the Curie temperature . In order to explain these changes the curveslg =f(1/T) and the Curie temperatures , obtained from the temperature dependence of the saturated magnetization J_s=f(T), were compared. Eight samples of basalts, 2 samples of haematite and magnetite were used to demonstrate the relation between and the changes in the pattern of the electric conductivity, caused by the variations of the exchangeable energy of ferrimagnetic minerals.     

Scientific objectives of the Solar Mesosphere Explorer mission

The 1981–82 Solar Mesosphere Explorer (SME) mission is described. The SME experiment will provide a comprehensive study of mesospheric ozone and the processes which form and destroy it. Five instruments will be carried on the spinning spacecraft to measure the ozone density and its altitude distribution from 30 to 80 km, monitor the incoming solar ultraviolet radiation, and measure other atmospheric constituent which affect ozone. The polar-orbiting spacecraft will be placed into a 3pm-3 am Sun-synchronous orbit. The atmospheric measurements will scan the Earth's limb and measure: (1) the mesospheric and stratospheric ozone density distribution by inversion of Rayleigh-scattered ultraviolet limb radiance, and the thermal emission from ozone at 9.6 m; (2) the water vapor density distribution by inversion of thermal emission at 6.3 m; (3) the ozone photolysis rate by inversion of the O₂(¹g) 1.27 m limb radiance; (4) the temperature profile by a combination of narrow-band and wide-band measurements of the 15 m thermal emission by CO₂; and, (5) theNO₂ density distribution by inversion of Rayleighscattered limb radiance at 0.439 m. The solar ultraviolet monitor will measure both the 0.2–0.31 m spectral region and the Lyman-alpha (0.1216 m) contribution to the solar irradiance. This combination of measurements will provide a rigorous test of the photochemical equilibrium theory of the mesospheric oxygen-hydrogen system, will determine what changes occur in the ozone distribution as a result of changes in the incoming solar radiation, and will detect changes that may occur as a result of meteorological disturbances.     

Identity of the characteristics of electrodynamic seismographs with non-standard periods of seismometers and galvanometers

Summary The maximum changes of magnification were determined for electrodynamic seismographs with standard characteristics and for some experimental long-period seismographs, the constants of which are given in Tab. 1, when the period of the seismometer or galvanometer has a deviation of not more than 5% from the standard value. Under the assumption of control of the other constants of the seismograph, identical amplitude and phase responses with a small change of the absolute magnification of the seismograph may be achieved with characteristicsAII ( ² >0.2), AIV ( ² 0.4), B ( ² >0.3) Nos28, 32 and33. This deviation can also be compensated by adjusting the optical distance. The procedure of adjusting the identical characteristics is suitable for systems with which an accurate setting of the period is difficult and for systems with an uncontrollable period, provided their values are within the limits of allowed deviations from the standard constants.     

Anisotropic magnetic susceptibility of rocks under mechanical stresses

Summary The magnetic susceptibility of a rock under a uniaxial compression () decreases along the axis of compression and increases along the direction perpendicular to the axis, with an increase of . Thus, the magnetic susceptibility of a compressed rock becomes anisotropic.The decrease of longitudinal susceptibility,K (), and the increase of transverse susceptibility,K (), are theoretically derived from a model of rock which assumes the uniaxial anisotropy and the isotropic magnetostriction of magnetic minerals in rocks and a random orientation of the minerals. Results show thatK () decreases toward zero whereasK () increases and approaches a finite asymptotic value with an increase of , and –(/)K () is twice as large as /K () for small values of . These results are in good agreement with experimental data.

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Zusammenfassung Die magnetische Suszeptibilität eines Steines unter zunehmender uniachsigen Druckspannung () nimmt ab längs der Achse der Druckspannung und nimmt zu längs der Richtung senkrecht der Achse. Somit wird die magnetische Suszeptibilität des gedrückten Steines anisotrop.Die Abnahme der longitudinalen Suszeptibilität,K (), und die Zunahme der transversalen Suszeptibilität,K (), werden theoretisch von einem Modell eines Steines hergeleitet, das die uniachsige Anisotropie, die isotrope Magnetostriktion, und eine nichtbevorzugte Orientierung der magnetischen Minerals im Stein annimmt. Die Ergebnisse zeigen, dass mit einer Zunahme des ,K () gegen Null abnimmt, währendK () zunimmt und sich einem begrenzten asymtotitschen Wert nähert und, dass für kleine Werte des , –(/)K () zweimal so gross wie /K () ist. Diese Ergebnisse stimmen gut mit den Versuchangaben überein.

     

Ionization above theF2-peak,as affected by the interplanetary gas

Summary The atmospheres of the earth, the sun and other bodies are surrounded by gas that is nearly uniform in number densityn and kinetic temperatureT, over spaces much greater than those occupied by the atmospheres. This gas may be called theambium of the atmosphere. In total it is much more massive than the atmosphere it encloses. The conditions in the ambium must powerfully affect the state of the outer atmosphere. In particular, there must be a continuous transition of the values ofn andT between the ambium and the atmosphere. In the case of the earth, the sun and other hot stars, both the ambium and the outermost part of the atmosphere will consist of atomic hydrogen. The temperature of the ambium will determine whether this hydrogen and that of the outermost atmosphere are mainly ionized or neutral.The nature of the terrestrial ambium depends on the extension of the sun's atmosphere. This atmosphere is hot and highly ionized in its inner parts. At some radius not yet known, the solar atmospheric gas must become cool and neutral. The state of the earth's outermost atmosphere depends greatly on whether the earth lies in the ionized or the neutral part of the sun's atmosphere, or in the solar ambium.Evidence will be presented favoring the view that the earth's ambium consists of ionized solar atmospheric hydrogen. If this be so, the outermost part of the earth's atmosphere is likewise hot and ionized. It must enclose an extensive layer of mainly neutral atomic hydrogen.The part of this work done at High Altitude Observatory was supported by the National Bureau of Standards and the Air Force Cambridge Research Center.     

Frequency dependent electrical properties of minerals and partial-melts

The resistance to current flow of minerals and partial-melts is a frequency dependent electrical property. Measurements of the frequency dependent electrical impedance of single crystal olivine, polycrystalline olivine, dunites, metapelites, and partial-melts, between 10^–4 and 10⁵ Hz, when plotted in the complex impedance plane, reveal arcs that correspond to different conduction mechanisms in the material being studied. In polycrystalline materials, two impedance arcs related to material properties (as opposed to electrode properties or electrode-sample interactions) are observed. Each impedance arc is activated over a distinct range of frequency, that is, the mechanisms occur in series. Based on experiments comparing single and polycrystalline impedance spectra, experiments on samples with different electrode configurations, and on samples of varying dimension, the mechanisms responsible for these impedance arcs are interpreted as grain interior conduction ( _gi ), grain boundary conduction (in polycrystalline materials; _gb ), and sample-electrode interface effects, from highest to lowest frequency, respectively. Impedance spectra of natural dunitic rocks reveal analogous behavior, that is, _gb and _gi add in series. The grain boundaries do not enhance the conductivity of any of the materials studied (a direct result of the observed series electrical behavior) and, under certain conditions, limit the total conductivity of the grain interior-grain boundary system. By examining the frequency dependence of the electrical properties of partial-melts, it is possible to gain information about microstructure and the distribution of the melt phase and to determine the conditions under which the presence of melt enhances the total conductivity. Impedance spectra of olivine-basalt partial-melts indicate that at least two conduction mechanisms occur in series over the frequency range 10^–4-10⁵ Hz, similar to the observed electrical response of melt-absent polycrystalline materials. In a sample containing isolated melt pockets the intermediate frequency grain boundary impedance arc is modified by the presence of melt indicating series conduction behavior. In a sample with an interconnected melt phase the high frequency grain interior impedance arc is modified by the melt phase, indicating the initiation of parallel conduction behavior. Because field EM response versus frequency curves are used to derive conductivity versus depth profiles, it is important to perform laboratory experiments to understand the frequency-dependent electrical behavior of Earth materials. Activation energies determined from studies that measure conductivity at a single frequency may be erroneous because of the shift of the dominant conduction mechanism with frequency as temperature is varied.