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  • Artikel  (23)
  • Coal mining  (12)
  • Tropical meteorology  (11)
  • 2010-2014
  • 1980-1984  (23)
  • 1950-1954
  • Geologie und Paläontologie  (23)
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  • Artikel  (23)
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  • Geologie und Paläontologie  (23)
  • Physik  (11)
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 463-482 
    ISSN: 1420-9136
    Schlagwort(e): Wave-wave interactions ; Monsoon variations ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Fourier analysis of the monthly mean northern hemispheric geopotential heights for the levels 700 mb and 300 mb are undertaken for the months of April through to August. The wave to wave and wave to zonal mean flow kinetic energy interactions are computed for specified latitude bands of the northern hemisphere during the pre-monsoon period (April to May) and monsoon period (June through to August) for bad monsoon years (1972, 1974, 1979) and for years of good monsoon rainfall over India (1967, 1973, 1977). Planetary scale waves (waves 1 to 4) are the major kinetic energy source in the upper atmosphere during the monsoon months. Waves 1 and 2 in particular are a greater source of kinetic energy to other waves via both wave to wave interactions as well as wave to zonal mean flow interactions in good monsoon years than in bad monsoon years. The zonal mean flow shows significantly larger gains in the kinetic energy with a strengthening of zonal westerlies in good monsoon years than in bad monsoon years.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 119 (1981), S. 922-933 
    ISSN: 1420-9136
    Schlagwort(e): Extreme precipitation ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The greatest one-day rain amounts recorded at individual stations in the country during the last 41-year period from 1940 onwards were examined for all observatories as well as State rain-gauge stations in an attempt to bring out up-to-date information on the greatest recorded point rainfall for the duration of one day. Outstanding one-day point rainfall amounts recorded prior to 1940 were also examined and have been included in this note along with their date and year of occurrence by way of comparison. A generalized chart has been prepared based on the percentage ratios of the greatest one-day rainfall to the mean annual rainfall of about 300 observatory stations distributed uniformly over the entire country. On the basis of Depth-Area-Duration (DAD) analyses of the most severe rainstorms which occurred over different plain areas of the country, it has been found that the 2 July, 1941, rainstorm gave the highest areal rain depths in the country for different areas. Comparison with similar areal rain depths of the tropical USA has shown that rain depths of the July, 1941, rainstorm were higher for all areas excepting the areas of 500 sq. miles (1295 sq. km) and 1000 sq. miles (2590 sq. km).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 615-625 
    ISSN: 1420-9136
    Schlagwort(e): Quasi biennial oscillations ; Total ozone ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Regular measurements of the atmospheric ozone in the Brazilian sector were started at Cachoeira Paulista (22.7°S, 45.0°W), and Natal (5.8°S, 35.2°W) in May 1974 and November 1978, respectively. The results of the total ozone measurements carried out at these two stations up to 1981 are presented in this communication and compared with other low-and mid-latitude stations. Although Natal is an equatorial station, it presents a prominent annual variation, and the average total ozone content is high compared to satellite measurements. During 1977–78, abnormally low values of total ozone were observed at Cachoeira Paulista. Some preliminary results about the QBO 9quasi-biennial oscillation) during 1974–81 are also presented.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 673-681 
    ISSN: 1420-9136
    Schlagwort(e): Atmospheric electricity ; Neutral droplets ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Streamers were injected into a large population of small droplets, of radii about 20 μm, confined to a given region of pre-determined shape on a photographic film, and situated in a gap between which a variable electric field can be applied. Results showed that the droplet region behaves like a dipole discharging from both ends if its inclination to the electric field is less than 45° and the field is not less than −230 kV/m at atmospheric pressure. We deduced that streamer intensification will occur at relatively low fields if there exists pockets of large number density of small droplets.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 483-494 
    ISSN: 1420-9136
    Schlagwort(e): Flood ; Precipitation ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The rainstorm of 17 to 21 July 1981 which caused exceptionally heavy rains and floods in arid Rajasthan, was analysed. It was observed that 7 stations in the rainstorm area broke their previous 80-year record of one-day rainfall, and two of these stations equalled their respective estimates of probable maximum precipitation (PMP). A comparison of areal raindepths of this rainstorm with the similar raindepths of past severe-most rainstorms of this region showed that this rainstorm gave unprecedented raindepths up to about 38 850 sq. km (i.e. 15 000 sq. miles) for a 3-day duration.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 495-502 
    ISSN: 1420-9136
    Schlagwort(e): Cloudiness ; Sunshine ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The relationship between point cloudiness and sunshine derived cloud cover in India is investigated using data collected from 33 stations. It has been found that point cloudiness, in general, overestimates sunshine derived cloud cover. The latitudinal dependence of the overestimation is discussed. The significance of the precise quantification of cloudiness in radiation budget studies is briefly mentioned.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 118 (1980), S. 775-782 
    ISSN: 1420-9136
    Schlagwort(e): Aerosol extinction ; Solar radiation ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Solar radiance measurements covering over seventeen months are analysed for a location beside the Lagos Lagoon. The aerosol extinction coefficient was generally higher in the dusty months than in the wet months. ‘Clean air’ estimates of the coefficient are made. Data on its wavelength dependence are also presented.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 119 (1980), S. 24-30 
    ISSN: 1420-9136
    Schlagwort(e): Radiation ; Tropical meteorology ; Turbidity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Analysis of turbidity measurements using a Volz sunphotometer, at three sites in India, two of them coastal and one inland, is reported. The sites are rural, far from industrial activity. After making an error analysis of the measurement technique the seasonal variations in turbidity parameters are interpreted in relation to the concurrent changes in relevant meteorological parameters like wind speed, wind direction, temperature and humidity. At coastal sites, the turbidity and the atmospheric salt concentration are found to be well correlated though the correlation coefficient varies between sites.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 67-78 
    ISSN: 1420-9136
    Schlagwort(e): Monsoon ; Transport ; Tropical meteorology ; Water vapour
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The advective monthly mean transfer of water vapour in the layer below 700 mbar is investigated for India for the years 1962 to 1972 and for the months January to September. The average zonal and meridional components of the transfer of water vapour for India are obtained. They are further averaged for different combinations of the pre-monsoon months from January to May and are correlated with the summer monsoon rainfall. The correlation coefficients for zonal transfer of water vapour are either negative or small positive for different combinations of the months mentioned above. The correlation coefficients for the meridional transfer of water vapour are positive. The maximum value is 0.74 for the March to May combination and is statistically significant at the 1% level. An extensive investigation is, therefore, made for the March to May averages of water vapour transfer for four broad regions of India. The parameters of water vapour transfer for these regions are compared with the threshold values and the prediction category, normal or drought, for the subsequent summer monsoon season is determined for all years. The correlation coefficient between the index of drought, as determined from parameters of water vapour transport and rainfall departure, is statistically significant at the 2% level.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 79-94 
    ISSN: 1420-9136
    Schlagwort(e): Monsoon ; Rainfall ; Tropical meteorology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The paper deals with an application of a stochastic model to the frequency and duration of precipitation events. With the aid of the model, the magnitudes ofmth highest rainfall amount in 24 hours' duration with 97.5% probability are obtained for various climatic regimes over a tropical monsoon region. There is good agreement between them-day minimum rainfall estimated through the model and the observed value. The model satisfactorily explains the frequency of the extreme rainfall event.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Pure and applied geophysics 120 (1982), S. 123-135 
    ISSN: 1420-9136
    Schlagwort(e): Tropical meteorology ; Atmospheric electricity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The results of atmospheric electric measurements over a twenty year period (1961–1980) are reviewed for Ibadan situated in the tropical rain forest of Nigeria. The aim is to present the data in an easily accessible form.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 1 (1983), S. 57-70 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; tunnel ; tunnelling machine ; tunnel support ; rock cutting
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary Some of the factors affecting the performance of a tunnel-boring machine in the Sea Drift tunnel at Dawdon Colliery are examined. These illustrate the potential for tunnelling machines in Coal Measures strata as a means for rapid excavation of a stable tunnel profile, and the difficulties likely to be encountered in zones of sheared or weak ground.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 43-49 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; strata control ; computer-aided design ; mine planning: steep seam working
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary Research into strata control has been pursued at Cerchar for the last 20 years, and has led to the definition of rules for the siting of new mine workings. These rules are drawn up as a function of the ‘volume of influence’ which is exerted by existing workings. To facilitate their application by the coal producer, a computer-aided design system for steep-seam faces has been developed on a minicomputer. The main features of the interactions which occur within the volume of influence of such faces are restated and the system which has been developed for design is described, with particular emphasis on the design stages which involved graphic systems and data base management.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 85-90 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; shaft lining ; concrete creep
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 171-173 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; subsidence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 305-321 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; finite difference analysis ; error analysis ; strata control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary Sources of error are investigated for a two-dimensional finite difference computer program designed to model strata deformation. The program calculates the displacements of a mesh of ‘mass points’, by the iterative solution of equations of equilibrium for the stresses acting on each mass point. The effect of errors on both displacement estimates and stress estimates is considered. Round-off errors are discussed analytically, while the effect of choosing too coarse a mesh density is demonstrated by comparison of two runs of the program with identical material properties, but different mesh densities. The influence of boundary conditions and the result of incomplete relaxation of the finite difference equations is estimated by comparison with Kirsch's analytical solution for a thin plate of finite width with a circular hole under unidimensional load. As a result of the analysis, estimators for stresses and displacements are derived, which make allowance for some of the sources of error; suitable boundary conditions for first and subsequent runs of the program are proposed; and a convergence criterion for the iterative process is suggested. These results are then applied to simulations of mining situations, together with various refinements of the basic model, such as separation and ‘slip’ between adjacent strata, and an allowance for failure of material.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 291-304 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; strata control ; finite difference analysis ; stochastic methods
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary A two-dimensional finite difference computer program, with the facility to represent stratified material by means of a mesh of ‘mass points’ with different material properties in each square of the mesh, is adapted to run on a mesh whose material properties are selected stochastically from a specified distribution. The program uses an iterative method to solve the equations of equilibrium, giving estimates of displacements and stresses. Lattices of normally distributed (zero mean, unit variance) random values are produced: lattices of statistically independent values and lattices whose values are spatially correlated, to give the effect of gradual variations resulting in regions of positive values and regions of negative values. These lattices are used to generate the material properties: Young's modulus, Poisson's ratio and density. Each property has a specified mean and standard deviation for each material in the model, and the precise values for each mass point are calculated from the relevant lattices. A simple model with a square opening is used to investigate the effect of this stochastic generation of material properties, by comparison of stresses and displacements near the opening for runs of the program with (1) deterministic and (2) stochastic properties. Similar lattices of random values are used to introduce a stochastic element in the criterion for failure of materials. This is applied to a more realistic simulation of a mining situation, where Mohr's Criterion is used, with a stochastic component, to determine whether failure has occurred at each point of the mesh.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 1 (1983), S. 283-294 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; strip mining ; operational research ; computer simulation ; surface mining
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary Optimization algorithms are developed to improve the selection of truck and shovel fleets for suface mine operations. These are based on performance estimation models developed by Fluor Utah (1977) and graphical display algorithms and other software within the SEAMPLAN system developed at Montana State University. The advantages and disadvantages of the method are considered.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 119-132 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; strata control ; rock pressure ; mine planning ; longwall mining
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary Astrata control system has been developed to improve mine planning and design in deep coal mines in West Germany, where redistributed stresses from longwall workings in weak strata create difficult support problems. The system involves theoretical, laboratory and underground observations and studies of strata and support performance. Examples of the system covered in detail include planning the position and support of a cross-cut; improving a face layout; planning a gateroad; planning strata bolting and planning longwall face layouts.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 253-259 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; mine ventilation ; air leakage ; stoppings in mine roadways ; ventilation network
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary This paper deals with the effects of air leakage from intake to return airways through a series of stoppings on the analysis of coal mine ventilation. The mathematical model which assumes continuous leakage along adjoining intake and return airways is reviewed, and a new mathematical approach is presented based upon the concentrated leakage through individual stoppings. The procedure incorporating the new method in the analysis of coal mine ventilation networks is also discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 2 (1984), S. 271-290 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; longwall mining ; subsidence ; rock deformation ; finite element analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary Some aspects of subsidence caused by longwall coal mining are analysed using the finite element method. Results of the analysis are compared with a true mine panel, where measurements on subsidence were available. Rock deformations in the overburden were modelled by using an elasto-plastic constitutive model. The study indicates that the shape of the subsidence profile can be predicted reasonably well by using nonlinear finite element analysis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 1 (1983), S. 253-260 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; geophysics ; borehole log
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Conclusion Geotechnical and lithology data can be reliably derived from borehole geophysical logs. The advantages of deriving geotechnical and lithology data directly from geophysical logs rather than from core examination is that the produced data is continuous, readily interpretable and consistent. In addition the technique is labour saving and cost cutting, especially since data may be extracted from cheaper rock-bitted boreholes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Geotechnical and geological engineering 1 (1983), S. 71-77 
    ISSN: 1573-1529
    Schlagwort(e): Coal mining ; mine gases ; mine ventilation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Conclusions Some bituminous coals, mostly of high volatile rank, sampled from various coalfields contained on average 0.5 m3 t−1 nitrogen and 0.13 m3 t−1. Nitrogen is released more readily than methane during coal winning but the volumes of nitrogen released are small compared with ventilation quantities and are only likely to be of significance for detailed oxygen deficiency studies.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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