منابع مشابه
An Improved Differential Strain Analysis Method for Super Deep Wells
The deeper a reservoir is, the smaller diameter the drilled full diameter cores have. It is difficult to conduct insitu stress experiments with conventional methods if the diameter of the full diameter cores is less than 6.0 cm, especially for cores abundant in natural fractures. In this paper, based on conventional Differential Strain Analysis (DSA) methods and wave velocity anisotropy methods...
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In Lund, Sweden productivity problems were encountered during flow testing of a 1927 m deep gravel packed screen completed well and it became apparent that well development was needed to increase productivity. A hydrojetting system using coiled tubing in combination with simultaneous pumping was developed and tested and found to be successful. To verify whether the well development improved the...
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Arsenic pollution in groundwater caused serious environment and health problem world widely. Few are reported for the occurrence and mechanisms of arsenic pollution in deep aquifers, though it is well documented by numerous study for arsenic enrichment in shallow groundwater. In this study, arsenic pollution was found in deep wells for drinking purpose. A total of 112 drinking groundwater sampl...
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We report the development of Al0.7Ga0.3N /AlN quantum wells with high internal quantum efficiency. All samples had identical well and barrier thickness but the III/V flux ratio was varied during growth by increasing the Ga flux. The luminescence spectra show single peaks which vary from 220 nm III /V 1 to 250 nm III /V 1 with internal quantum efficiency varying from 5% to 50%, respectively. To ...
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We report the development of complete structural AlGaN-based deep-ultraviolet light-emitting diodes with an aluminum thin layer for increasing light extraction efficiency. A 217% enhancement in peak photoluminescence intensity at 294 nm is observed. Cathodoluminescence measurement demonstrates that the internal quantum efficiency of the deep-UV LEDs coated with Al layer is not enhanced. The emi...
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ژورنال
عنوان ژورنال: Nature
سال: 1873
ISSN: 0028-0836,1476-4687
DOI: 10.1038/007283c0