Shock waves and the chemical structure of interstellar clouds     

M. Y. Amin  M. S. El-Nawawy  M. A. El-Shalaby 《Astrophysics and Space Science》1991,185(2):277-294

In this paper we study the effect of shock waves on the chemical structure of the interstellar clouds. A model of molecular cloud has been assumed. The chemistry is investigated in a time dependent model. Our chemical network contains 56 species in 251 reactions to including molecules of the elements H, O, C, N, S, and Si.The results indicate that the calculated fractional abundance of the molecules NS, H₂O, CN, NH, CO, and SO agrees well with the observations. The molecules OH, H₂S, CS, H₂CS, HS, NO, SiO, CH, CH₂, CH₃, HCO, C₂, and HCN reach high post-shock abundances.  相似文献   

Experiments on uni-directional and nonlinear wave group shoaling     

Kimmoun  Olivier  Hsu  Hung-Chu  Hoffmann  Norbert  Chabchoub  Amin 《Ocean Dynamics》2021,71(11-12):1105-1112

Ocean Dynamics - We report an experimental study addressing the characteristic hydrodynamic transformations of unstable wave groups as well as JONSWAP wave fields propagating from deep-water...  相似文献   

Effect of the spectral shape of ground motion records on the collapse fragility assessment of degrading SDOF systems     

Norouzi  Amin  Poursha  Mehdi 《地震工程与工程振动(英文版)》2021,20(4):925-941

The main purpose of this paper is to study the collapse capacity of single degree of freedom(SDOF) systems and to produce fragility curves as well as collapse capacity spectra while considering a broad range of structural parameters, including system degradation, the P-Δ effect, ductility capacity and the post-capping stiffness ratio. The modified IbarraKrawinkler deterioration model was used to consider hysteretic behavior. A comprehensive study was conducted to extract the collapse capacity spectrum of SDOF systems with a wide range of periods, varying from 0.05 to 4 s, to cover short, intermediate and long periods. Incremental dynamic analysis(IDA) was performed for SDOF systems to identify the condition in which the collapse capacity of the system is determined. The IDAs were performed using different sets of seismic ground motions. The ground motion records were categorized into different sets based on three spectral shape parameters, including the epsilon, Sa Ratio and N_p. The collapse fragility curves of SDOF systems with different periods were extracted to illustrate the collapse capacity at different probability levels. The results show that structural degradation and ductility as well as the spectral shape parameters significantly affect the collapse capacity of SDOF systems. On the other hand, the post-capping stiffness ratio and small levels of the P-Δ effect do not remarkably change collapse capacity. Also, the collapse capacity of SDOF systems is more sensitive to the records categorized based on Sa Ratio and N_p than those classified based on epsilon.  相似文献   

An ActiveX control for embedding GPS capability in custom applications     

Khalid Amin Khan  Gulraiz Akhter  Zulfiqar Ahmad 《GPS Solutions》2011,15(4):433-439

An ActiveX GPS control is presented which can be used to develop software applications with GPS functionality. It translates the NMEA 0183 interface GPS instructions and triggers event procedures which are used by applications to access the GPS data. It provides position data in the form of geographic coordinates as well as Universal Transverse Mercator (UTM) projected coordinates. This control is recommended for the development of general purpose GPS-enabled applications which do not require a high level of accuracy. A Visual Basic project is also included to demonstrate the use of various features of this control. Finally, some real-time software applications are discussed which have been developed using this control. These applications include static point averaging; path tracking; and imagery-based position mapping.  相似文献   

Effects of Land Transformation on Water Quality of Dal Lake,Srinagar, India   总被引：3，自引：0，他引：3  

Arshad Amin  Shahab Fazal  Ahmad Mujtaba  Sudhir Kumar Singh 《Journal of the Indian Society of Remote Sensing》2014,42(1):119-128

The present study focuses on the growing human needs which drive the native boatmen of the Kashmir valley (Hanjis) that bring the interchanges of land use/cover classes in Dal lake and its environs of Srinagar city. Further to assesses the effects of land transformation on lake water quality. The results suggested that the significant land use changes have been occurred during the past of 30 years (1981–2011). Besides this, interchange of land has taken place between different land uses classes, which has resulted into lake water pollution due the addition of various nutrients/pollutant discharged from Hanjis activities. The study concludes that the land transformation has converted the once fresh water lake much deteriorated pond.  相似文献   

Application of Landsat-8 and ASTER satellite remote sensing data for porphyry copper exploration: a case study from Shahr-e-Babak,Kerman, south of Iran     

Morteza Safari  Amin Beiranvand Pour 《国际地球制图》2013,28(11):1186-1201

Abstract

The Shahr-e-Babak region located in the Kerman metallogenic belt is one of the high potential segments of Urumieh–Dokhtar magmatic arc for porphyry copper and epithermal gold mineralization in the south of Iran. This high potential zone encompasses several porphyry copper deposits under exploitation, development and exploration stages. The aim of this study is to evaluate Landsat-8 data and comparison with the Advanced Spaceborne Thermal Emission and Reflection Radiometer data-sets for mapping hydrothermal alteration zones related to Cenozoic magmatic intrusions in Shahr-e-Babak region. Previous studies have proven the robust application of ASTER in lithological mapping and mineral exploration; nonetheless, the Landsat-8 data have high capability to map and detect hydrothermal alteration zones associated with porphyry copper and epithermal gold mineralization. In this investigation, several band combinations and multiplications, developed selective principal component analysis and image transformations were developed for discriminating hydrothermal alteration zones associated with porphyry copper mineralization using Landsat-8 data.  相似文献   

Mapping alteration mineral zones and lithological units in Antarctic regions using spectral bands of ASTER remote sensing data     

Amin Beiranvand Pour  Mazlan Hashim  Yongcheol Park  Jong Kuk Hong 《国际地球制图》2013,28(12):1281-1306

Abstract

Geological mapping is one of the primary tasks of remote sensing. Remote sensing applications are especially useful when extreme environmental conditions inhibit direct survey such as in Antarctica. In this investigation, a satellite-based remote sensing approach was used for mapping alteration mineral zones and lithological units using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data in the Oscar II coast area, north-eastern Graham Land, Antarctic Peninsula. Specialized band ratios and band combinations were developed using visible and near infrared, shortwave infrared (SWIR) and thermal infrared spectral bands of ASTER for detecting alteration mineral assemblages and lithological units in Antarctic environments. Constrained Energy Minimization, Orthogonal Subspace Projection and Adaptive Coherence Estimator algorithms were tested to ASTER SWIR bands for detecting sub-pixels’ abundance of spectral features related to muscovite, kaolinite, illite, montmorillonite, epidote, chlorite and biotite. Results indicate valuable applicability of ASTER data for Antarctic geological mapping.  相似文献   

Closure to ＂Discussion on ＇Optimum placement and characteristics of velocity-dependent dampers under seismic excitation＇ by SA Mousavi and AK Ghorbani-Tanha＂ by Izuru Takewaki     

Seyed Amin  Mousavi Amir  K.  Ghorbani-Tanha 《地震工程与工程振动(英文版)》2013,12(4):681-682

The authors would like to thank the discusser for his considerations and comments. The discusser believes that some of the derived formulations need to be referred to his previously published works and also some related studies have not been cited.  相似文献   

Investigating the time dynamics of monthly rainfall time series observed in northern Lebanon by means of the detrended fluctuation analysis and the Fisher-Shannon method     

Michele Lovallo  Amin Shaban  Talal Darwich  Luciano Telesca 《Acta Geophysica》2013,61(6):1538-1555

We investigate the time dynamics of monthly rainfall series intermittently recorded on seven climatic stations in northern Lebanon from 1939 to 2010 using the detrending fluctuation analysis (DFA) and the Fisher-Shannon (FS) method. The DFA is employed to study the scaling properties of the series, while the FS method to analyze their order/organization structure. The obtained results indicate that most all the stations show a significant persistent behavior, suggesting that the dynamics of the rainfall series is governed by positive feedback mechanisms. Furthermore, we found that the Fisher Information Measure (the Shannon entropy power) seems to decrease (increase) with the height of the rain gauge; this indicates that the rainfall series appear less organized and less regular for higher-located stations. Such findings could be useful for a better comprehension of the climatic regimes governing northern Lebanon.  相似文献   

Growing electrostatic modes in the isothermal pair plasma of the pulsar magnetosphere     

U. A. Mofiz  M. R. Amin  P. K. Shukla 《Astrophysics and Space Science》2012,337(1):177-184

It is shown that a strongly magnetized isothermal pair plasma near the surface of a pulsar supports low-frequency (in comparison to electron cyclotron frequency) toroidal electrostatic plasma modes in the equatorial region. Physically, the thermal pressure coupled with the magnetic pressure creates the low frequency oscillations which may grow for particular case of inhomogeneities of the equilibrium magnetic field and the pair plasma density.  相似文献