Assessment of regional air pollution distribution by point cumulative semivariogram method at Erzurum urban center, TURKEY     

F. S. Turalioglu  H. Bayraktar 《Stochastic Environmental Research and Risk Assessment (SERRA)》2005,19(1):41-47

In the assessment of air quality, regional distribution and dispersion with distance are important, together with the variations of pollutants in time. On this occasion, the point cumulative semi-variogram (PCSV) method is used in order to find simply regional distribution of pollutants of Erzurum urban centre. This method is based simply on the summation of square differences in air pollutant concentrations between different sites. Monthly regional variation maps of Erzurum are constructed by finding radius of influence (for SO₂, from 1000 m to 3500 m and, for TSP, 1000–2000 m) and PCSV scattering diagram data at different levels by using monthly average sulphur dioxide (SO₂) and total suspended particulate (TSP) matter concentrations in 2001–2002 winter season. Consequently, the air pollution distribution of Erzurum is assessed.  相似文献   

Pseudo‐dynamic seismic response of reinforced concrete frames infilled with non‐structural brick masonry     

F. Colangelo 《地震工程与结构动力学》2005,34(10):1219-1241

This paper presents pseudo‐dynamic test results on the in‐plane seismic behaviour of infilled frames. Thirteen single‐storey, single‐bay, half‐size‐scale, reinforced concrete‐frame specimens, most of which infilled with non‐structural masonry made of perforated bricks and cement mortar are tested. The infills are in contact with frames, without any connector; openings are not covered. The frames are different in their strength and details, reinforcement grade, and aspect ratio. Seismic input is the 1976 Tolmezzo (Friuli, Italy) ground acceleration, to which specimens are subjected two times: virgin and damaged by the previous test. The global seismic response of initially virgin infilled specimens considerably differs from that of bare specimens. This follows a dramatic change of properties: compared to a bare frame, the initial stiffness increases by one order of magnitude, and the peak strength more than doubles. The peak drift lessens; however, the displacement ductility demand does not. The energy demand is greater. Nevertheless, the influence of infill decreases as damage proceeds. Displacement time histories of damaged specimens are quite similar. At the local level, infill causes asymmetry and concentration of the frame deformation. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Evolutionary aseismic design and retrofit of structures with passive energy dissipation     

G. F. Dargush  R. S. Sant 《地震工程与结构动力学》2005,34(13):1601-1626

A new computational framework is developed for the design and retrofit of building structures by considering aseismic design as a complex adaptive process. For the initial phase of the development within this framework, genetic algorithms are employed for the discrete optimization of passively damped structural systems. The passive elements may include metallic plate dampers, viscous fluid dampers and viscoelastic solid dampers. The primary objective is to determine robust designs, including both the non‐linearity of the structural system and the uncertainty of the seismic environment. Within the present paper, this computational design approach is applied to a series of model problems, involving sizing and placement of passive dampers for energy dissipation. In order to facilitate our investigations and provide a baseline for further study, we introduce several simplifications for these initial examples. In particular, we employ deterministic lumped parameter structural models, memoryless fitness function definitions and hypothetical seismic environments. Despite these restrictions, some interesting results are obtained from the simulations and we are able to gain an understanding of the potential for the proposed evolutionary aseismic design methodology. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Sediment Distribution Around Glacially Abraded Bedrock Landforms (Whalebacks) at Lago Tranquilo, Chile     

Neil F. Glasser  Stephan Harrison 《Geografiska Annaler: Series A, Physical Geography》2005,87(3):421-430

Whalebacks are convex landforms created by the smoothing of bedrock by glacial processes. Their formation is attributed to glacial abrasion either by bodies of subglacial sediment sliding over bedrock or by individual clasts contained within ice. This paper reports field measurements of sediment depth around two whaleback landforms in order to investigate the relationship between glacigenic deposits and whaleback formation. The study site, at Lago Tranquilo in Chilean Patagonia, is situated within the Last Glacial Maximum (LGM) ice limits. The two whalebacks are separated by intervening depressions in which sediment depths are generally 0.2 to 0.3 m. Two facies occur on and around the whalebacks. These facies are: (1) angular gravel found only on the surface of the whalebacks, interpreted as bedrock fracturing in response to unloading of the rock following pressure release after ice recession, and (2) sandy boulder‐gravel in the sediment‐filled depressions between the two whalebacks, interpreted as an ice‐marginal deposit, with a mixture of sediment types including basal glacial and glaciofluvial sediment. Since the whalebacks have heavily abraded and striated surfaces but are surrounded by only a patchy and discontinuous layer of sediment, the implication is that surface abrasion of the whalebacks was achieved primarily by clasts entrained in basal ice, not by subglacial till sliding.  相似文献   

Shear velocity structure in the Aegean area obtained by inversion of Rayleigh waves   总被引：2，自引：0，他引：2  

E. E. Karagianni  C. B. Papazachos  D. G. Panagiotopoulos  P. Suhadolc  A. Vuan  G. F. Panza 《Geophysical Journal International》2005,160(1):127-143

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Full moment tensor retrieval for two earthquake swarms at the Alps–Dinarides junction     

S. Kravanja  G. F. Panza 《Geophysical Journal International》2005,160(2):683-694

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Moment release in the Lower Rhine Embayment, Germany: seismological perspective of the deformation process     

J. Schmedes  S. Hainzl  S.-K. Reamer  F. Scherbaum  K.-G. Hinzen 《Geophysical Journal International》2005,160(3):901-909

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Comment on 'On sensitivity kernels for 'wave-equation' transmission tomography' by de Hoop and van der Hilst     

F. A. Dahlen  Guust Nolet 《Geophysical Journal International》2005,163(3):949-951

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Desert vegetation and timing of solar radiation     

J.C. Walton  F. Martinez-Gonzalez  R. Worthington 《Journal of Arid Environments》2005,60(4):697-707

Timing and amount of solar radiation were examined as factors influencing the distribution of seven perennial plants on a small mountain located in the Chihuahuan Desert. Average direct beam solar radiation fluxes at differing times throughout the day and year were estimated with computer calculations. Principal components analysis was used to reduce the number of solar radiation parameters and include the maximum available information with a manageable number of variables. The remaining solar radiation parameters were compared to plant distributions using redundancy analysis and generalized additive models. Unimodal, bimodal, and monotonic responses were all found depending upon the species and solar radiation parameter. Niche separation at this location depends upon the timing as well as the amount of solar radiation.  相似文献   

Shallow seismic trapping structure in the San Jacinto fault zone near Anza, California   总被引：3，自引：0，他引：3  

M. A. Lewis  Z. Peng †  Y. Ben-Zion  F. L. Vernon 《Geophysical Journal International》2005,162(3):867-881

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