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31.
32.
The present article discusses the stress–strain behavior and critical state parameters of the dredged Chennai marine clay stabilized with low cement content (2.5–10%). A series of one-dimensional consolidation tests and consolidated undrained tri-axial tests are performed on the cement stabilized dredged Chennai marine clay to evaluate the critical state parameters (λ, κ, M, Г, N) for varying cement contents and curing days. The results show that the slope of the critical state line M increases with an increase in the cement content. The parameter λ for the treated marine clay increases up to a cement content of 7.5% followed by a reduction. The parameter κ decreases with the addition of cement content. Finally, empirical formulations are proposed to predict the critical state parameters as the functions of the cement's contents and curing days.  相似文献   
33.
Ocean Science Journal - The Gray mussel Crenomytilus grayanus occurs in high density in the shallow rocky subtidal zone on the east coast of Korea, where the mussel dominates the shallow subtidal...  相似文献   
34.
With the availability of high spatial resolution space-borne sensors, the wave parameters like wave propagation direction, wavelength of the dominant wave etc., are estimated from the Fourier spectra of ocean scene imageries. The hybrid optical processor is the most suitable for the analysis of imageries, since it utilises the parallel processing capability of the optical processor for generating the Fourier spectra. An attempt has been made to use a hybrid processor with wedge-ring sampling detector array for the estimation of wave parameters and the results are encouraging.  相似文献   
35.
A new method for semi-automatic identification of oil slick on ocean/sea surface from space borne imagery using optical power spectra has been suggested. This method is based on the fact that the presence of the oil slick in the ocean suppresses the normal wave pattern that will be present in the ocean area without oil slick and the power spectra of the image area having the oil slick will be devoid of the peak corresponding to the dominant wave. In addition, the general shape of the oil slick will increase the low frequency content in the power spectra. The method has been applied for test areas containing oil slicks and the results are encouraging.  相似文献   
36.
We present a UBV CCD photometric study of four open clusters, NGC 7245, King 9, IC 166 and King 13, located between   l = 90°  and 135°. All are embedded in a rich Galactic field. NGC 7245 and King 9 are close together in the sky and have similar reddenings. The distances and ages are: NGC 7245, 3.8 ± 0.35 kpc and 400 Myr; King 9 (the most distant cluster in this quadrant), 7.9 ± 1.1 kpc and 3.0 Gyr. King 13 is 3.1 ± 0.3 kpc distant and 300 Myr old. King 9 and IC 166 (4.8 ± 0.5 kpc distant and 1 Gyr old) may be metal-poor clusters  ( Z = 0.008)  , as estimated from isochrone fitting. The average value of the distance of young clusters from the Galactic plane in the above longitude range and beyond 2 kpc (−47 ± 16 pc, for 64 clusters) indicates that the young disc bends towards the southern latitudes.  相似文献   
37.
Excessive total and differential settlement at the intersection of a surcharged prefabricated vertical drain (SPVD) and a rigid piled embankment on soft ground during the post-construction period leads to considerable time and costs being spent on repetitive remedial works in the future. This paper presents a sustainable design approach for high and long embankment filling on soft clay at the approach to the structure by introducing the intersection of an SPVD at the transition to a rigid piled embankment in order to regulate the differential settlement between the two conventional ground treatment approaches. This paper also presents a full-scale field study to validate the performance of the intersection of the SPVD at the transition to the rigid piled embankment. By introducing the intersection ground treatment, post-construction settlement and differential settlement are minimised significantly, while the post-construction total settlement at the rigid transition piled embankment (TPE) zone is reduced significantly by about 80 to 95% of the total settlement, as compared to a conventional TPE.  相似文献   
38.
Suspended sediments deposition at estuary affects marine life in coastal ecosystem. Particle size distribution (PSD) is used to find settling velocity of suspended sediments. In this study, a new image capturing system for size analysis (ICS4S) method using digital camera-based image capturing technique for determining PSD is proposed and validated. Image of suspended sediments is acquired using a low-cost setup developed, and ImageJ software is used for image processing. The PSD results obtained using ICS4S method is well correlated with hydrometer test and the Shen method. The proposed ICS4S method is easy to understand and implement both in laboratory and field.  相似文献   
39.
We present the optical spectroscopic study of two classical Be stars, 59 Cyg and OT Gem obtained over a period of few months in 2009. We detected a rare triple-peak H α emission phase in 59 Cyg and a rapid decrease in the emission strength of H α in OT Gem, which are used to understand their circumstellar disks. We find that 59 Cyg is likely to be rapid rotator, rotating at a fractional critical rotation of ~0.80. The radius of the H α emission region for 59 Cyg is estimated to be R d/R ? ~ 10.0, assuming a Keplerian disk, suggesting that it has a large disk. We classify stars which have shown triple-peaks into two groups and find that the triple-peak emission in 59 Cyg is similar to ζ Tau. OT Gem is found to have a fractional critical rotation of ~0.30, suggesting that it is either a slow rotator or viewed in low inclination. In OT Gem, we observed a large reduction in the radius of the H α emission region from ~6.9 to ~1.7 in a period of three months, along with the reduction in the emission strength. Our observations suggest that the disk is lost from outside to inside during this disk loss phase in OT Gem.  相似文献   
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