Optimal Port Design Minimizing Standing Waves with A Posteriori Long Term Shoreline Sustainability Analysis     

Cook  Megan  Bouchette  Frédéric  Mohammadi  Bijan  Sprunck  Léa  Fraysse  Nicolas 《中国海洋工程》2021,35(6):802-813

China Ocean Engineering - Optimization theory is applied to a coastal engineering problem that is the design of a port. This approach was applied to the redesign of La Turballe Port in order to...  相似文献   

LRS Bianchi-I anisotropic cosmological model with dominance of dark energy     

Anil Kumar Yadav  Bijan Saha 《Astrophysics and Space Science》2012,337(2):759-765

The present study deals with spatially homogeneous and anisotropic locally rotationally symmetric (LRS) Bianchi type I cosmological model with dominance of dark energy. To get the deterministic model of Universe, we assume that the shear scalar (σ) in the model is proportional to expansion scalar (θ). This condition leads to A=B ⁿ , where A, B are metric potential and n is positive constant. It has been found that the anisotropic distribution of dark energy leads to the present accelerated expansion of Universe. The physical behavior of the Universe has been discussed in detail.  相似文献   

Interacting Scalar And Spinor Fields In Bianchi Type I Universe Filled With Magneto-Fluid     

Bijan?SahaEmail author 《Astrophysics and Space Science》2005,299(2):149-158

Self-consistent system of spinor, scalar and BI gravitational fields in presence of magneto-fluid and Λ term is considered. Assuming that the expansion of the BI universe is proportional to the σ₁ component of the shear tensor, exact solutions for the metric functions, as well as for scalar and spinor fields are obtained. For a non-positive Λ, the initially anisotropic space–time becomes isotropic one in the process of expansion; whereas for Λ > 0, an oscillatory mode of expansion of the BI model occurs. PACS numbers: 03.65.Pm and 04.20.Ha  相似文献   

Shake table tests on a mass eccentric model with base isolation   总被引：1，自引：0，他引：1  

Bijan Samali  Yi Min Wu  Jianchun Li 《地震工程与结构动力学》2003,32(9):1353-1372

A mass eccentric structure is usually more seismically vulnerable than its concentric counterpart because of the coupled torsional–translational response of such structures. In this work, dynamic characteristics and response of a five‐storey benchmark model with moderate mass eccentricity were investigated using a shake table, simulating four different ground motions. The effectiveness of laminated rubber bearings (LRB) and lead‐core rubber bearings (LCRB) in protecting eccentric structures was examined and evaluated in relation to translational and torsional responses of the benchmark model. It was observed that both translational and torsional responses were significantly reduced with the addition of either a LRB or LCRB isolated system regardless of the nature of ground motion input. The LRB were identified to be more effective than LCRB in reducing model relative displacements, the relative torsional angle as well as accelerations, and therefore provided a better protection of the superstructure and its contents. On the other hand, LCRB rendered a smaller torsional angle and absolute displacement of the base isolation system, hence a more stable structural system. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Westerly jet stream and past millennium climate change in Arid Central Asia simulated by COSMO-CLM model     

Bijan Fallah  Sahar Sodoudi  Ulrich Cubasch 《Theoretical and Applied Climatology》2016,124(3-4):1079-1088

This study tackles one of the most debated questions around the evolution of Central Asian climate: the “Puzzle” of moisture changes in Arid Central Asia (ACA) throughout the past millennium. A state-of-the-art Regional Climate Model (RCM) is subsequently employed to investigate four different 31-year time slices of extreme dry and wet spells, chosen according to changes in the driving data, in order to analyse the spatio-temporal evolution of the moisture variability in two different climatological epochs: Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). There is a clear regime behavior and bimodality in the westerly Jet phase space throughout the past millennium in ACA. The results indicate that the regime changes during LIA show a moist ACA and a dry East China. During the MCA, the Kazakhstan region shows a stronger response to the westerly jet equatorward shift than during the LIA. The out-of-phase pattern of moisture changes between India and ACA exists during both the LIA and the MCA. However, the pattern is more pronounced during the LIA.  相似文献   

Effect of a Non‐Ionic Surfactant on Xylene Removal in a Scoria‐Compost‐Based Biofilter          下载免费PDF全文

Mohammad Mehdi Amin  Amir Rahimi  Bijan Bina  Fazel Mohammadi Moghadam  Heshmatollah Nourmoradi  Mohsen Heidari 《洁净——土壤、空气、水》2016,44(12):1759-1765

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The role of viscoelastic damping on retrofitting seismic performance of asymmetric reinforced concrete structures     

Alam  Zeshan  Zhang  Chunwei  Samali  Bijan 《地震工程与工程振动(英文版)》2020,19(1):223-237

The primary purpose of this research is to improve the seismic response of a complex asymmetric tall structure using viscoelastic(VE) dampers. Asymmetric structures have detrimental effects on the seismic performance because such structures create abrupt changes in the stiffness or strength that may lead to undesirable stress concentrations at weak locations. Structural control devices are one of the effective ways to reduce seismic impacts, particularly in asymmetric structures. For passive vibration control of structures, VE dampers are considered among the most preferred devices for energy dissipation. Therefore, in this research, VE dampers are implemented at strategic locations in a realistic case study structure to increase the level of distributed damping without occupying significant architectural space and reducing earthquake vibrations in terms of story displacements(drifts) and other design forces. It has been concluded that the seismic response of the considered structure retrofitted with supplemental VE dampers corresponded well in controlling the displacement demands. Moreover, it has been demonstrated that seismic response in terms of interstory drifts was effectively mitigated with supplemental damping when added up to a certain level. Exceeding the supplemental damping from this level did not contribute to additional mitigation of the seismic response of the considered structure. In addition, it was found that the supplemental damping increased the total acceleration of the considered structure at all floor levels, which indicates that for irregular tall structures of this type, VE dampers were only a good retrofitting measure for earthquake induced interstory deformations and their use may not be suitable for acceleration sensitive structures. Overall, the research findings demonstrate how seismic hazards to these types of structures can be reduced by introducing additional damping into the structure.  相似文献   

A coupled model analyses on the interaction between oceanic eddies and tropical cyclones over the Bay of Bengal     

Anandh  Thanka Swamy  Das  Bijan Kumar  Kuttippurath  J.  Chakraborty  Arun 《Ocean Dynamics》2020,70(3):327-337

Ocean Dynamics - The Bay of Bengal (BOB) region of Indian Ocean is affected by numerous tropical cyclones during pre- and post-monsoon seasons when various eddies are generated in the central and...  相似文献   

Single- and multiple-tuned liquid column dampers for seismic applications     

Fahim Sadek  Bijan Mohraz  H. S. Lew 《地震工程与结构动力学》1998,27(5):439-463

Design parameters for single- and multiple-tuned liquid column dampers for reducing the response of structures to seismic excitations are presented. A deterministic analysis is carried out using 72 earthquake ground motion records to determine the tuning ratio, tube width to liquid length ratio, and head loss coefficient corresponding to a given mass ratio for single-tuned liquid column dampers. A similar analysis is performed to determine the central tuning ratio, tuning bandwidth, and grouping of dampers for multiple-tuned liquid column dampers. The study indicates that by properly selecting the design parameters, single- and multiple-tuned liquid column dampers can reduce the response of structures to seismic excitation by up to 45 per cent. Design examples using single- and multiple-tuned liquid column dampers in a bridge and a ten-storey building are presented to illustrate how the parameters are selected and to demonstrate the performance of the devices under different ground excitations. The response of several structures with tuned liquid column dampers is compared with that using tuned mass dampers where it is shown that both devices result in comparable reductions in the response. © 1998 John Wiley & Sons, Ltd. This paper was produced under the auspices of the U.S. Government and it is therefore not subject to copyright in the U.S.  相似文献   

Particle Swarm Optimization Algorithm for Neuro-Fuzzy Prospectivity Analysis Using Continuously Weighted Spatial Exploration Data     

Roshanravan  Bijan  Aghajani  Hamid  Yousefi  Mahyar  Kreuzer  Oliver 《Natural Resources Research》2019,28(2):309-325

Natural Resources Research - Classification of spatial exploration data for exploration targeting using neuro-fuzzy models means that the many spatial values have to be simplified and assigned to a...  相似文献