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Computerised open pit design with special reference to dynamic programmingKordestani, S. S. January 1988 (has links)
No description available.
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The study of characterization microstructure defects of LiAlO2 crystal.Huang, Hui-chun 19 February 2008 (has links)
"none"
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Opname van kalsium-45 deur appelbome by verskillende vogpeile en die induksie van bitterpitHanekom, Alwyn Nicolaas 25 September 2014 (has links)
Ph.D. (Botany) / Please refer to full text to view abstract
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The importance of the facial pit of the Northern Pacific rattlesnake (Crotalus viridis oreganus) under natural conditions in southern British ColumbiaPreston, William Burton January 1964 (has links)
The facial pits characterizing the snake subfamily Crotalinae have been demonstrated to be important as thermoreceptors in detecting the presence of prey animals and in directing the stroke towards them. So specialized a receptor as the pit organ, if it is to survive, must be functionally effective. If this organ is important in locating prey under natural conditions it would be expected that if these pits were destroyed this importance would be reflected in growth rates, weight changes,, or survival. In twenty of forty snakes collected in the spring of 1963 the pits were destroyed by electric cautery. After weighing, measuring, and marking, the snakes were released at the point of capture. The growth of the recaptured cauterized and non-cauterized snakes was compared. In addition, controlled tests were made with the recaptured snakes, using live mice and light-proof boxes to determine the effectiveness of cautery. A significant statistical difference was found in the growth rates of the females, the cauterized snakes growing more slowly. No difference was found in the growth rates of the males. However, the controlled tests indicates the pits to be important to the males as well as to the females. Weight changes were too variable to reveal differences between normal and cauterized snakes and no difference in survival was evident between the two treatments. To overcome the effect of individual variation in growth rate further study is required of larger samples over a longer time period. / Science, Faculty of / Zoology, Department of / Graduate
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EARLY STAGE WATER CAP OXYGEN CONSUMPTION TRENDS WITHIN THE FIRST COMMERCIAL SCALE OIL SANDS PIT LAKE, BASE MINE LAKE.Risacher, Florent Frédéric January 2017 (has links)
Bitumen exploitation in Alberta’s oil sand region generates considerable amounts
of waste including tailings and process-affected water that needs reclamation. Water
capped tailings technology (WCTT) is currently being assessed as a potential wet
reclamation strategy in the oil sand by the commission of Base Mine Lake (BML), the first
commercial scale Pit Lake. Pit Lakes consist of ~40m of fluid fine tailings (FFT) deposited
in old mine pit covered with a ~10m water cap. In order to be successful, pit lakes much
achieve the ecological roles of a natural lake, which includes colonization of the water by
macrofauna therefore necessitating the water cap to be oxic. Due to the reductive nature of
the tailings, oxygen consuming constituents (OCC) such as methane, sulfide and ammonia
are released from the FFT into the water cap potentially posing a threat to the success of
the reclamation. Additional seasonal effects such as stratification and ice cover may further
affect oxygen consumption by isolating parts of the water cap therefore allowing
accumulation of OCC. Results shows that BML thermally stratifies during the summer and
winter and that oxygen persist throughout the water cap despite reaching low level at the
FFT-water interface (FWI) during summer. Consistent with the FFT acting as an OCC
source, aqueous CH 4 and NH 4+ concentrations were highest closer to the FWI, decreasing
upwards into the water cap. Using linear regression CH 4 was shown to be an important
OCC during the summer of 2015 while NH 4+ and CH 4 were both important for the summer
of 2016 highlighting the emergence of nitrification in BML. Detailed analysis of seasonal
data revealed that accumulation of OCC below the hypolimnion depletes oxygen and favors
methanotrophic activity. Results from both studies suggest that methanotrophs have a
competitive advantage at low oxygen levels against nitrifiers. / Thesis / Master of Science (MSc) / Bitumen extraction in Alberta’s oil sand region generates substantial amounts of
waste including tailings that needs reclamation. Pit Lakes have been proposed as a
reclamation strategy, where tailings are deposited into a mined-out pit and covered with a
water cap. To achieve the reclamation goal, the lake must be able to sustain life and must
therefore maintain an oxic water cap. The underlying tailings poses a threat to the
oxygenation of the lake because of the constant release of compounds that have the
potential to consume oxygen. Additional seasonal effects due to temperature change may
further affect oxygen consumption by isolating parts of the water cap. In this thesis the
results of two years of field sampling and analyses show that despite active oxygen
consumption from tailings-released compounds, oxic status is achieved in the upper layer
of the lake during summer and under ice.
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An Analysis of Morphometric and Morphologic Relationships in Lunar Pit Craters: The Role of WaterMalinski, Peter T. 25 August 2015 (has links)
No description available.
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Molecular phylogeography and venom evolution of Trimeresurus stejnegeri in TaiwanCreer, Simon January 2000 (has links)
No description available.
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'Voices in Frickley' : the struggles of the miners at a Yorkshire colliery 1984-1993Nightingale, J. E. January 1997 (has links)
No description available.
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Mineral resource management principles that need to be incorporated in Anglogold Ashanti LTD east and west Africa regionBender, Wynand 31 October 2006 (has links)
Student Number : 0112584H -
MSc research project -
School of Mining Engineering -
Faculty of Engineering and the Built Environment / With the acquisition by AngloGold Ashanti Ltd of open pit mines in East and
West Africa with possible addition of Greenfield and Brownfield operations, the
emphasis of this research document was to improve the current open pit mines in
this region. By identifying Mineral Resource Management (MRM) as a way to
improve and manage operating practices, additional value and the accompanied
risks have been identified. It was also realised that the current traditional,
predominantly financial indicators are becoming increasingly inadequate, thus
looking at alternative operating principles. Subsequent to this, proposals have
been made to acquire the necessary production and cost change by integrating
structure, strategy, systems, style, skills, staff and the defined goals as proposed in
this document. Using a “process-based” approach integrating (best) operating
practices, concepts such as: living out the company’s strategic values; a learning
organisation; better informed decision-making; people management; self-directed
teams; continuous improvement; asset and capital management; integrated
information systems; and an improved internal and external customer relationship
be obtained.
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On the development of thermally etched morphology of Co1-XO-MgO polycrystalsHuang, Chang-ning 02 August 2004 (has links)
Abstrate
Co1-XO polycrystals, prepared by sintering at 1600oC with or without Mg2+-dopant ,were thermally etched at 400-1500oC for 10 min-12hr and studied by scanning electron microscopy regard to the effects of temperature and Mg2+-dopant on etching development. In low etching temperature (400-800 oC), vacancy relaxation process and spinel precipitate produced on the surface of Co1-XO-MgO polycrystals. In high etching temperature (1500 oC), Co1-XO epitaxy was spread on the steps and ledges. In addition, Co1-XO was thermally etched at 1500 oC for 10min to 12hr, we found triangular to hexagonal etch pits were produced. However, Mg2+-dopant changed the geometric shape of the pit opening. Besides, growth hillocks with corrugated terrace steps at edge and a pit at center showed that growth and etching of crystal can happen in the same time.
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