Applying Zeeman Doppler imaging to solar spectra     

G. A. J. Hussain  S. H. Saar  A. Collier Cameron 《Astronomische Nachrichten》2004,325(3):245-245

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Evaluation of gridded precipitation data in the Hindu Kush–Karakoram–Himalaya mountainous area     

Shakir Hussain  Guoyu Ren  Iqtidar Hussain  Dongmei Han  M.H. Zaman 《水文科学杂志》2017,62(14):2393-2405

The accurate measurement of precipitation is crucial for hydrological studies. This is especially true for the Hindu Kush–Karakoram–Himalaya (HKKH) mountain region, which is characterized by high spatiotemporal precipitation variability. The paucity of raingauges makes it difficult to measure precipitation in this region precisely. We conducted evaluation of TMPA 3B42V7 and APHRO 1101 in the HKKH area on a daily basis at a spatial resolution of 0.25°?×?0.25°, using 27 raingauges. Statistically, the largest error in the gridded data arose mainly from elevation, followed by volumetric error and Nash–Sutcliffe efficiency. Overall, the TMPA data have a poor correlation with ground observations in the HKKH area, especially for higher altitudes. The western areas are relatively more underestimated and the Karakoram shows higher frequency of bias in the TMPA retrievals. This method could help improve the satellite precipitation estimation algorithm as it considers local physiography and climatic factors.  相似文献   

Geochemistry of Dharwar ultramafics and the Archaean mantle     

V. Divakara Rao  K. Satyanarayana  S.M. Naqvi  S.M. Hussain 《Lithos》1975,8(2):77-91

Geochemical and petrological studies on serpentinised ultramafics of Kadakola, Mysore State, India, indicate that the Archaean mantle beneath the Indian Shield was of peridotitic in nature. This protomantle in the Archaean period was undifferentiated with higher concentrations of siderophile and transitional elements.  相似文献   

Inventory of degraded lands of Palamau district, Bihar — A remote sensing approach     

Sanjay K Gupta  M Hussain  M Ahmed  A S Pandey  P Singh  K M Saini  S N Das 《Journal of the Indian Society of Remote Sensing》1998,26(4):161-168

In this study, an attempt has keen made for the identification, categorisation and mapping of degraded lands in Palamau district of Bihar using remotely sensed data (IRS-1A, raise colour composite, on 1:50,000 scale), It was observed that water erosion is the main cause of land degradation affecting 6.27 per cent area of the district, of which 5.22 per cent is subjected to severe to very severe erosion and remaining 1.05 per cent is moderately to severely gulleid land Degradation due to rock quarries, mine spoils and dumps accounted for only 0.01 per cent of the district area. Degraded lands were mostly confined to agricultural areas (4.76%) follwed by forest lands (1.10%) and opert-scrub/pastures (0.42%), respectively, Subdivision-wise categorisation of degraded lands was also attempted for efficient location-speeific reclamation planning and easy monitoring.  相似文献   

A critical review on waste paper sorting techniques   总被引：1，自引：1，他引：0  

M. O. Rahman  A. Hussain  H. Basri 《International Journal of Environmental Science and Technology》2014,11(2):551-564

Efficient waste paper recycling has a significant role in the sustainable environment. Recyclable waste paper as a fundamental ingredient of municipal solid wastes (MSWs) is indeed an “urban ore”. Waste papers are considered as the solid recovered fuel which is recovered from MSW. Recyclable waste papers are segregated into various grades to produce high-quality products. Moreover, sorted paper streams save energy, chemicals, and water, as well as reduce sludge and rejects. Information technology is widely integrated with the waste management industry into its operations such as recycling, reuse, segregating based on categories and so on. This review article focuses on the life cycle of waste paper and existing waste paper sorting techniques. In the paper industry, many types of sensors are used in different mechanical and optical waste paper sorting systems. Such sensors include lignin, gloss, stiffness, mid-infrared, infrared, and color sensors. In this review, also described the effectiveness of different waste paper sorting systems, and finally, recommended appropriate waste paper sorting techniques based on effectiveness and low-cost implementation.  相似文献   

Brick kiln exhaust as a source of polycyclic aromatic hydrocarbons (PAHs) in the surrounding soil and plants: a case study from the city of Peshawar, Pakistan     

F. Akbar Jan  Sabir Khan  M. Ishaq  M. Naeem  I. Ahmad  Sajjad Hussain 《Arabian Journal of Geosciences》2014,7(1):13-19

The purpose of the present study was to investigate the effects of brick kiln exhaust on the quantity of polycyclic aromatic hydrocarbons in surrounding soils and plants. In Pakistan, a big problem is the rapid conglomeration of the brick kilns in out skirt of nearly all urban centers to cope with the rapid construction work in big cities. A huge amount of low-grade coal, rubber, tires is used in non-scientific manner. The study was conducted in the City of Peshawar the capital of Kyber Pakhtunkhwa where many brick kilns are located in the periurban areas. Soil and medicinal plants samples were collected from different locations around the bricks kiln and were analyzed for selected polycyclic aromatic hydrocarbons (PAHs), i.e., benzo(a)pyrene, anthracene, chrysene, flourene, flouranthene, phenanthrene, naphthalene, and acenapthylene. Quantitative and qualitative analysis was carried out by UV spectrophotometer and high-performance liquid chromatography. Benzo[a]pyren and Chrysene were found to be the most abundant compounds. The total load of PAHs in the central location was found to be 0.4014 mg/kg. General trend of PAHs distribution was such that the concentration of individual PAHs was found to increase with depth clearly indicating their absorption in the soil. PAHs concentration increased with the distance up to 300 m and then gradual decreased which showed their movement with the water and air. The PAHs load was found high in the leaves as compared to stem and roots. This high load in the aerial parts indicated their excretion route as well as air deposition.  相似文献   

Investigation of the properties of electrostatic IA solitary wave structures in negative ion magneto-plasmas with superthermal electrons     

S. Hussain  S. Ali Shan  N. Akhtar  M. M. Masud 《Astrophysics and Space Science》2014,352(2):605-612

A rigorous theoretical investigation is carried out in analyzing the excitation of electrostatic ion acoustic (IA) solitary wave (SW) structures in two dimensional negative ion magneto-plasmas with superthermal electrons (following κ type distribution). The Zakharov-Kuznetsov (ZK) equation is derived by employing the well known reductive perturbation method, and the analytical solution of ZK equation assists to find out the SW profiles along with their properties. The consequences of different plasma parameters (regarding our considered plasma system) variation on SW structures has been studied. It is found that magnetic field intensity, superthermal parameter κ and temperature of positive and negative ions as well as their densities significantly modify the basic characteristics (amplitude, width, etc.) of the SW waves. A comparison of the SW structures is also presented when the electrons are Maxwellian to when they are superthermal. The relevance of the findings of this work with astrophysical plasmas is briefly pointed out.  相似文献   

The regional and the seasonal variability of extreme precipitation trends in Pakistan   总被引：1，自引：0，他引：1  

Mian Sabir Hussain  Seungho Lee 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(4):421-441

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Hubble Space Telescope observations of SV Cam – II. First derivative light-curve modelling using phoenix and atlas model atmospheres     

S. V. Jeffers  J. P. Aufdenberg  G. A. J. Hussain  A. Collier Cameron  V. R. Holzwarth 《Monthly notices of the Royal Astronomical Society》2006,367(3):1308-1316

The variation of the specific intensity across the stellar disc is an essential input parameter in surface brightness reconstruction techniques such as Doppler imaging, where the relative intensity contributions of different surface elements are important in detecting star-spots. We use phoenix and atlas model atmospheres to model light curves derived from high precision (signal-to-noise ratio ≃ 5000) Hubble Space Telescope ( HST ) data of the eclipsing binary SV Cam (F9V+K4V), where the variation of specific intensity across the stellar disc will determine the contact points of the binary system light curve. For the first time, we use χ² comparison fits to the first derivative profiles to determine the best-fitting model atmosphere. We show the wavelength dependence of the limb darkening and that the first derivative profile is sensitive to the limb-darkening profile very close to the limb of the primary star. It is concluded that there is only a marginal difference (<1σ) between the χ² comparison fits of the two model atmospheres to the HST light curve at all wavelengths. The usefulness of the second derivative of the light curve for measuring the sharpness of the primary's limb is investigated, but we find that the data are too noisy to permit a quantitative analysis.  相似文献   

The coronal structure of AB Doradus determined from contemporaneous Doppler imaging and X-ray spectroscopy   总被引：1，自引：0，他引：1  

G. A. J. Hussain  M. Jardine  J.-F. Donati  N. S. Brickhouse  N. J. Dunstone  K. Wood  A. K. Dupree  A. Collier Cameron  F. Favata 《Monthly notices of the Royal Astronomical Society》2007,377(4):1488-1502

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