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61.
An approach based on the behaviour of human genome is developed to efficiently provide a general framework for optimizing
the use of space technology in surveying networks design. The developed approach attempts to apply the successful self-organizing
principles based upon the biological evolution to artificial intelligence. It mimics the phenomena of natural selection observed
in nature to achieve its goals by continuously adopting a population of candidate solutions and improving its performance
over successive generations. The goal of adaptation is to find the best solution that optimizes the design of a surveying
network based on the use of satellite observations. This network can be defined as a set of stations, co-ordinated by a series
of sessions formed by placing receivers on the stations. The problem is to search for the best order for observing these sessions
to give the best observation schedule at minimum cost. The obtained results prove the effectiveness of the developed technique
in term of solution quality and computational efforts.
The Corresponding Author in formed me that his address is likely to change soon. Please contact me, leick@spatial.maine.edu
for the latest on this change. 相似文献
62.
Genotype and environment interaction effect on yield of cotton under naturally salt stress condition
Y. Ali Z. Aslam F. Hussain 《International Journal of Environmental Science and Technology》2005,2(2):169-173
Thirteen genotypes of cotton developed through hybridization and mutation breeding techniques were evaluated during two consecutives years 2002-03-04 on eight locations covering most of the area of Punjab province including Faisalabad, Toba Tek Singh and Jhang. The eight sets of experiments were conducted in the naturally highly saline sodic soils, EC ranges from 7.8–36.1 d/Sm, pH=8.1–8.8, SAR=10.1–40.5, Saturation percentage 31.3–40.8 and texture Sandy Clay loam and Clay loam. The seed yield data was collected at maturity and stability parameters were computed to know genotypic environment interaction and varietals performance. The combined analysis of variance showed highly significant variance in case of varieties, locations and varieties x environment (Lin) also showed highly significant differences. It means that genotypes exhibited different behavior in different locations/environments which is due to their different genetic make up. The behavior may be cross over (in which significant change in ranking order occurs from one environment to another) or cross over nature (in which case the ranking of genotypes remains constant across environments and the interaction is significant because of change in the magnitude of response) depending upon the ranking order of genotypes performance under different environments. In our study only S-12 behavior was of almost non cross over nature, while others had cross over type of interaction. Based on over all seed yield cotton variety NIAB-999 and CIM-707 produced highest seed yield cotton (3.2 t/ha, 3.17t/ha). The lowest seed yield cotton was noted in S-12 (1.86 t/ha). All the three parameters of stability i.e. overall mean seed yield cotton, regression coefficient and standard deviation to regression provided clear evidence that variety NIAB-999 and CIM-707 produced maximum stable yield compared to S-12. 相似文献
63.
B.S. Sukhija D.V. Reddy P. Nagabhushanam Syed Hussain V.Y. Giri 《Hydrogeology Journal》1996,4(2):70-88
In order to mine lignite from the Neyveli opencast mines, about 200 km south of Madras, India, the Neyveli aquifer has been undergoing depressurisation continuously for almost three decades. To gain insight into the aquifer hydrodynamics, environmental-isotope and chloride measurements on selected groundwater samples were initiated two decades ago, and detailed studies were undertaken during 1985–91. This article demonstrates the effect of large-scale groundwater withdrawals on the hydrologic regime and the effects on environmental chloride and isotopic distributions. A feature common to both the radiocarbon and chloride data of 1991 is their marked variation in a small area between the recharge zone and the mine area where pumping is concentrated. Furthermore, an excellent correlation exists between the temporal increase in the apparent radiocarbon ages of groundwater sampled in 1991 and 1985 and the corresponding lowering of potentiometric levels. Isochlors based on 1991 and 1985 data also indicate a changed hydrologic regime. In certain areas, heavy withdrawals have resulted in increased groundwater salinity. 相似文献
64.
The mechanism of222Rn release into fracture fluids by direct alpha-recoil, lattice and grain boundary/micro-crack diffusion is discussed. Experimental measurements of222Rn release into surrounding air and water phases have been made for crystalline rock specimens with well defined surface areas. The222Rn flux from an infinite plane surface and hence the effective diffusion length of222Rn in the rock matrix has been estimated.The222Rn flux from plane crystalline rock surfaces has been used in conjunction with a simple hydrological model of the reservoir to calculate the222Rn content of the return fluids of a geothermal doublet circulation system. For given production rate and piezometric difference between the injection and production wells, the222Rn content of the return fluid is dependent upon the distribution of flow path lengths and fracture apertures in the reservoir. Matching of the calculated and experimental222Rn contents of the return fluids has been used to select appropriate parameters for the reservoir model and hence to estimate the extent of the heat-transfer surface. The model estimates the fracture width of the flow paths, total swept surface area and fracture volume within the reservoir. 相似文献
65.
The rare earth element patterns of the gneisses of Bastar and Bundelkhand are marked by LREE enrichment and HREE depletion
with or without Eu anomaly. The spidergram patterns for the gneisses are characterized by marked enrichment in LILE with negative
anomalies for Ba, P and Ti. The geochemical characteristics exhibited by the gneisses are generally interpreted as melts generated
by partial melting of a subducting slab. The style of subduction was flat subduction, which was most common in the Archean.
The rare earth patterns and the multi-element diagrams with marked enrichment in LILE and negative anomalies for Ba, P and
Ti of the granitoids of both the cratons indicate interaction between slab derived melts and the mantle wedge. The subduction
angle was high in the Proterozoic. Considering the age of emplacement of the gneisses and granitoids that differs by ∼ 1 Ga,
it can be assumed that these are linked to two independent subduction events: one during Archaean (flat subduction) that generated
the precursor melts for the gneisses and the other during the Proterozoic (high angle subduction) that produced the melts
for the granitoids. The high values of Mg #, Ni, Cr, Sr and low values of SiO2 in the granitoids of Bastar and Bundelkhand cratons compared to the gneisses of both the cratons indicate melt-mantle interaction
in the generation of the granitoids. The low values of Mg#, Ni, Cr, Sr and high values of SiO2 in the gneisses in turn overrules such melt-mantle interaction. 相似文献
66.
Study of groundwater recharge processes is vital for quantification of total natural recharge to the aquifers. One of the
recharge processes demonstrated earlier by tracer experiments in the unsaturated zone is that of piston flow movement of soil
moisture. Based on this recharge process, environmental tritium, chloride and injected tritium studies have been carried out
extensively in various geological environs of India. The purpose of this paper is to evaluate the validity of the piston flow
concept in different geological environs viz. consolidated fractured and weathered granites, semi-consolidated sandstones
and unconsolidated alluvial tracts, and quantify the contribution from this process as well as that from the preferential
flow mechanism using different tracers. Analysis of tracer data demonstrates that the preferential flow recharge process contributes
very significantly (an average of 75% of total recharge) in the case of fractured granites and is important (an average of
33% of total recharge) for semi-consolidated sandstones, whereas the preferential flow recharge component is minimal in unconsolidated
alluvial tracts (piston flow model is applicable). These findings necessitate re-evaluation of the total natural recharge
potential of the above mentioned geological environs in view of the significant preferential flow recharge that is evidenced
and estimated.
Electronic Publication 相似文献
67.
G. A. J. Hussain J.-F. Donati A. Collier Cameron J. R. Barnes 《Monthly notices of the Royal Astronomical Society》2000,318(4):961-973
We compare surface brightness and magnetic field surface maps for the K0 dwarf AB Doradus, obtained using two independently developed Zeeman Doppler imaging codes. We find that even the fine structure in the two sets of images shows excellent agreement. Magnetic field maps appear to be less sensitive to line-modelling effects than brightness maps. We argue that these results point to the consistency and reliability of Doppler imaging techniques even when using poorly sampled data sets, provided that the spectra used are of sufficiently high signal-to-noise ratio. 相似文献
68.
69.
Prerona Das Abhijit Mukherjee Syed Aaquib Hussain Md. Shahid Jamal Kousik Das Ashok Shaw Mrinal K. Layek Probal Sengupta 《水文研究》2021,35(1):e14002
Groundwater depletion has been an emerging crisis in recent years, especially in highly urbanized areas as a result of unregulated exploitation, thus leaving behind an insufficient volume of usable freshwater. Presently Ganges river basin, the sixth largest prolific fluvial system and sustaining a huge population in South Asia, is witnessed to face (i) aquifer vulnerability through surface waterborne pollutant and (ii) groundwater stress due to summer drying of river as a result of indiscriminate groundwater abstraction. The present study focuses on a detailed sub-hourly to seasonally varying interaction study and flux quantification between river Ganges and groundwater in the Indian subcontinent which is one of the first documentations done on a drying perennial river system that feeds an enormous population. Contributing parameters to the total discharge of a river at its middle course on both temporal and spatial scale is estimated through three-component hydrograph separation and end-member mixing analysis using high-resolution water isotope (δ18O and δ2H) and electrical conductivity data. Results from this model report groundwater discharge in river to be the highest in pre-monsoon, that is, 30%, whereas, during post-monsoon the contribution lowers to 25%; on the contrary, during peak monsoon, the flow direction reverses thus recharging the groundwater which is also justified using annual piezometric hydrographs of both river water and groundwater. River water-groundwater interaction also shows quantitative variability depending on river morphometry. The current study also provides insight on aquifer vulnerability as a result of pollutant mixing through interaction and plausible attempts towards groundwater management. The present study is one of the first in South Asian countries that provides temporally and spatially variable detailed quantification of baseflow and estimates contributing parameters to the river for a drying mega fluvial system. 相似文献
70.