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11.
The demand for modular steel buildings (MSBs) has increased because of the improved quality, fast on-site installation, and lower cost of construction. Steel braced frames are usually utilized to form the lateral load resisting system of MSBs. During earthquakes, the seismic energy is dissipated through yielding of the components of the braced frames, which results in residual drifts. Excessive residual drifts complicate the repair of damaged structures or render them irreparable. Researchers have investigated the use of superelastic shape memory alloys (SMAs) in steel structures to reduce the seismic residual deformations. This study explores the potential of using SMA braces to improve the seismic performance of typical modular steel braced frames. The study utilizes incremental dynamic analysis to judge on the benefits of using such a system. It is observed that utilizing superelastic SMA braces at strategic locations can significantly reduce the inter-storey residual drifts. 相似文献
12.
Maged Marghany Arthur P. Cracknell Mazlan Hashim 《International Journal of Applied Earth Observation and Geoinformation》2009
This paper introduces a modified formula for the fractal box counting dimension. The method is based on utilization of the probability distribution formula in the fractal box count. The purpose of this method is to use it for the discrimination of oil spill areas from the surrounding features, e.g., sea surface and look-alikes in RADARSAT-1 SAR Wide beam mode (W1) and Standard beam mode (S2) data have been collected under different wind speeds. The results show that the new formula of the fractal box counting dimension is able to discriminate between oil spills, look-alike areas and pixels of the size of a single ship. The W1 mode data illustrate an error standard deviation of 0.05, thus performing a better discrimination of oil spills as compared to S2 mode data. We conclude that automatic detection and discrimination of oil spill and other sea surface features can be opertionalized by using the new formula for fractal box counting. 相似文献
13.
Hend Ahmed Ibrahim Hussein Adam Ricka Tomas Kuchovsky Maged Mostafa El Osta 《Arabian Journal of Geosciences》2017,10(7):170
The demand for water is rapidly increasing in Egypt, because of high population and agriculture production growth rate, which makes research of water resources necessary. The regional multi-aquifer system of the Miocene–Pleistocene age is discharged in Wadi El Natrun area. Intensive aquifer overexploitation and agricultural development in the area are related to groundwater quality deterioration. Hydrochemical and hydrogeological data was evaluated to determine the groundwater origin and quality in the south-eastern part of wadi, which appears to be more significant for water supply owing to lower groundwater salinity. The dominance of the high mineralised Cl groundwater type was found; however, also less mineralised SO4 and HCO3 types were identified there. Based on the ion relations, halite and gypsum dissolution and ion exchange are the most important hydrochemical processes forming the groundwater chemical composition. The Cl dominated groundwater matches the discharge part of the regional hydrogeological system. Contrary, the presence of HCO3 and SO4 hydrochemical types corresponds to the infiltration and transferring parts of the hydrogeological system indicating the presence of zones conducting low mineralised groundwater. The discharge area of the over-pumped aquifer in Wadi El-Natrun lies 23 m beneath the sea level with the shoreline being at the distance of 100 km, thus there is a real risk of seawater intrusion. Using the hydrochemical facies evolution diagram, four samples in the centre of the discharge area indicate advanced seawater intrusion. The zones of the highest demand for groundwater quality protection were indicated based on a spatial pattern of hydrogeochemical composition. 相似文献
14.
Maged M. A. Hussein 《Arabian Journal of Geosciences》2018,11(24):768
The best evaporation estimate method for Alexandria Eastern Harbor has been derived following the evaluation of performance of five evaporation estimate methods, namely, (1) Bowen ratio energy balance (BREB), (2) De Bruin–Keijman (DK), (3) Priestley–Taylor (PT), (4) Brutsaert–Stricker (BS), and (5) Penman (PM), based on two consecutive summer seasons of 2010 and 2011 data. Different statistical measurements of goodness of fit, namely, coefficient of determination (R2), root mean square error (RMSE), relative bias (RB), and index of agreement (D) have been chosen for the evaluation of the performance. When the Bowen ratio is known a priori, the DK and PT methods have been found the best evaporation estimate methods. The responses of the three methods BREB, DK, and PT were found comparable to each other, while the PM method response differed to match with the responses of the other three methods. The Bowen ration (β) of 0.05 and Priestley–Taylor (PT) coefficient (α) of 1.23 derived from the analysis can be extended for evaporation estimates in Alexandria Eastern Harbor, Egypt. 相似文献
15.
16.
This paper presents a new approach for modeling shoreline change due to wave energy effects from remotely sensed data. The
airborne AIRSAR and POLSAR data were employed to extract wave spectra information and integrate them with historical remotely
sensed data such as aerial photography data to model the rate of change of the shoreline. A partial differential equation
(PDE) of the wave conversion model was applied to investigate the wave refraction patterns. The volume of sediment transport
at several locations was estimated based on the wave refraction patterns. The shoreline change model developed was designed
to cover a 14-km stretch of shoreline of Kuala Terengganu in Peninsular Malaysia. The model utilized data from aerial photographs,
AIRSAR, POLSAR, ERS-2, and in situ wave data. The results show that the shoreline rate of change modeled from the quasi-linear
wave spectra algorithm has a significant relationship with one estimated from historical vector layers of aerial photography,
AIRSAR, and POLSAR data. With the quasi-linear algorithm, an error of ±0.18 m/year in shoreline rate of change determination
was obtained with C
vv band. 相似文献
17.
Maged Marghany 《International Journal of Applied Earth Observation and Geoinformation》2003,4(4):279-294
The impact of wave spectra modulation transfer function (MTF) in shoreline change model accuracy has been presented. The MTF consisted of real aperture radar (RAR) and velocity-bunching which is utilized to map the wave spectra observed from ERS-1 into the observed real ocean wave spectra. Based on this information, the shoreline change model have developed. Two hypotheses were concerned with the shoreline change model based on ERS-1 wave spectra. First, there is a significant difference between RAR and velocity-bunching modulations for ERS-1 wave spectra modeling. Second, this significant difference is induced a different spatial variation for shoreline change pattern.This study shows that there was the significant difference between velocity-bunching and quasi-linear models. The study shows that velocity-bunching model produces wave spectra pattern approximately close to the real ocean wave compared to the quasi-linear model. The error percentage occurred with velocity-bunching and quasi-linear models were 33.5 and 46.7%, respectively. The highest rate of erosion occurred to the shore south of Chendering with −5 m per year and the highest rate of sedimentation occurred to north of Chendering headland with 3 m per year. It can be concluded that ERS-1 data could be used to model shoreline change and identify the locations of erosion and sedimentation. The sedimentation was occurred due to the effect of lowest wave spectra energy captured along the range direction while the erosion was occurred due to highest spectra energy captured near azimuth direction. 相似文献
18.
3-D reconstruction of coastal bathymetry from AIRSAR/POLSAR data 总被引：1，自引：0，他引：1
This paper introduces a new method for reconstructing three-dimensional (3D) coastal bathymetry changes from Airborne AIRSAR/POLSAR synthetic aperture data. The new method is based on integration between fuzzy B-spline and Volterra algorithm. Volterra algorithm is used to simulate the ocean surface current from AIRSAR/POLSAR data. Then, the ocean surface current information used as input for continuity equation to estimate the water depths from AIRSAR/POLSAR data. This study shows that 3D ocean bathymetry can be reconstructed from AIRSAR/POLSAR data with root mean square error of ±0.03 m. 相似文献
19.
Mohamed A. El-Assar Abdel-Monem T. Abdel-Hameed Esam Zahran Maged El Osta 《Arabian Journal of Geosciences》2017,10(22):491
The Late Cretaceous (Campanian-Maastrichian), low-grade phosphorite sequence of East Sibaiya, Aswan area, which is known as the Duwi (phosphate) or Sibaiya Formation, is usually intercalated with marl, oyster limestone, and chert beds. These strata, which crop out in a generally east–west trending belt spanning the middle latitudes of Egypt, are phosphorite-rich sediments and of great economic importance. Representative samples were collected from the investigated area at several localities (e.g., Umm Tundubah-2 and Wadi El-Batur) and 200 kg of phosphate rocks was used for upgrading processes of low-grade phosphorites of the East Sibaiya area. The upgrading processes included two techniques: the first technique (gravity separation) comprises crushing, sieving, gravity separation by a shaking table, and magnetic separation. This technique raised the P2O5 in the head sample from 24.73 to 31.91% as a phosphate concentrate. The second technique (flotation technique) depends on certain flotation parameters such as pH, grain size, and phosphate collector dose (i.e., oleic acid). The flotation technique increased the P2O5% from 24.73 to 31.16% as a final product of the phosphate concentrate. These data were confirmed by X-ray fluorescence analyses of major elements. 相似文献
20.
Abdlrahem Maged A. El Naggar M. Hesham 《Geotechnical and Geological Engineering》2021,39(5):3669-3688
Geotechnical and Geological Engineering - Hollow bar micropiles (HBMP) have been popular for some time due to their fast installation and efficient load transfer mechanism. In the construction of... 相似文献