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Space-group character tablesKennedy, John Matthew January 1989 (has links)
No description available.
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Statistical software and an example of a regression packageDuncombe, P. January 1988 (has links)
No description available.
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STUDY OF FLOW AND TRANSPORT IN FRACTURED GRANITIC ROCKNdiweni, Cliford 17 May 2013 (has links)
The hydrogeology of the Tono basin, Japan, is strongly inuenced by the hydraulic
properties of faults, especially the main Tsukiyoshi fault, which extends
through the centre of the assessment area and has an E-W strike. According to the
results of borehole investigations, the fault has N800W strike, 700 dip, 10 ô 30m
width and approximately 30m vertical off-set. Hydraulic head discontinuities over
the main fault in the basin are about 40 m as a result of the low permeability of the
fault acting as a barrier to ow perpendicular to it. The fracture data from the Tono
basin was analysed in order to establish a correlation between geologic/geometric
attributes of a fracture and associated permeability of the interval that contains the
fracture, if any. Pressure response transients to excavation of two shafts that are
monitored at various boreholes within the study site show that proximity to a fault
is a key attribute that determines the ability of the fracture to conduct water. The
responses in boreholes that are close to the fault are vertically invariant, indicating
a large vertical permeability. This is not the case in boreholes that are further
from the main fault, where there is depth dependence in the pressure responses.
Near the fault, the damage zone seems to be equilibrating the heads between otherwise
unconnected aquifers. The Tsukiyoshi fault therefore acts as barrier to ow
perpendicular to it but also acts as conduit to vertical ow and ow parallel to the
fault. A three-dimensional model that simulates groundwater ow in the Tono basin
is constructed in order to study the dynamic uid ow before and after it was disturbed
by production and the excavation of the shafts. In the steady-state calculation,
the model predicts that the hydraulic head at depth in boreholes near the fault
is near the land surface. This condition indicates high vertical permeability in those
boreholes.
This thesis introduces a new approach of using pressure response data to do
an inversion calculation for the effective porosity of the granite. Pressure response
transients have been analysed using a numerical inversion procedure to estimate
the specic storage of the granite. The specic storage was calculated using the
pressure response data and ranged from 4:12 10ô7 to 8:93 10ô6mô1.
These values of the specic storage were used to do a transport calculation
in order to study the impact of the main fault on the transportation of hypothetical
contaminants in the basin. Particle tracking was used to investigate and demonstrate
the effects of the fault on path lines. The fault was found to have a strong inuence
on the transportation of contaminants. The general trend of the transportation of
the contaminants follows groundwater ow from the northern high elevations toward
the southern low elevation. This shows that the contaminants are transported
mainly by advection. However, this trend is interrupted by the Tsukiyoshi fault
that blocks horizontal ow and sends water toward the surface. An interesting feature
demonstrated by the model is that, within the fault core, no contaminants were found. The contaminants rise through the high-permeability damage zone and cross
over the fault through the weathered granite. However, at depths where the water
changes direction slowly because of the fault barrier to horizontal ow, the contaminants
seem to be able to cross the fault. The explanation is that diffusion becomes
the dominant mode of transport at the point where the water moves at slow velocities.
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THE PRIVATISATION OF PUBLIC HOUSING IN SOUTH AFRICA: INCREMENTAL UPGRADING PROCESSES IN MANGAUNGSefika, Moeketsi Simon 17 May 2013 (has links)
The argument in this dissertation is that housing studies focus mainly on the politicaleconomy
paradigms and ignore the role played by other social theories. On the one hand,
conventional economic theory, mainly built on new-Liberal principles, suggests that
privatisation is required to ensure that markets work better. In the housing field,
privatisation is mainly seen as a way to ensure the initiation of a secondary housing
market. On the other hand, Neo-Marxist views argue that privatisation leads to a range of
negative impacts, such as eventual homelessness and the unaffordable nature of housing
bonds. The main problem with these two political and economic viewpoints is that they
are blind to other social theories and ignore, to a large degree, the historical context of
housing, especially in South Africa. The debates in this study point out that the pathdependency
theory (with historical methodology as a sub-approach) in housing policy
discourses provides additional understanding of privatisation, especially in the South
African context. In contradiction to general observation, housing processes in South
Africa may be locked in their own trajectory, and they may not be similar to those in the
parent colonial power such as Britain.
This study identifies a policy and research gap in privatisation. It is the first attempt to
assess the privatisation of housing in South Africa through empirical evidence since the
introduction of the Discount Benefit Scheme two decades ago. The international
literature shows that there has been an effort in both developed and developing countries
to privatise rental housing stock. This move is related to the overwhelming pro-market
policy developments after the Second World War. Neo-Liberal and Neo-Marxist thinkers put forward various opinions for and against the process. With South Africa having had
strong economic and political ties with Britain during apartheid, the South African
government also privatised the nearly 500 000 state-owned housing units. Researchers in
South Africa also made postulations that were either Neo-Liberal or Neo-Marxist in
assessing the future possible impact of housing privatisation, this despite the work of
Turner and Tipple on the social context of housing.
The dissertation tests the original argument of the political-economy continuum by
interrogating the empirical evidence obtained from the suburb of Rocklands,
Bloemfontein. In this environment, tenants improve the state-subsidised core houses
through what Tipple terms âtransformationsâ, which are more a response to social needs
than to economic imperatives. The empirical analysis looks at the outcomes of housing
privatisation relating to the physical effects on housing after transformations, the
processes involved in transformations that accentuate self-dependence and
resourcefulness and the capacity of tenants to borrow from the market and trade their
improved assets in the market.
The main findings from the empirical evidence support a key theoretical assumption that
housing debates should look beyond the binary political-economic debate. The findings
in the study refute the political-economic assumptions forwarded in the Neo-Liberal and
Neo-Marxist theories. However, the findings in the study support Tippleâs contentions on
the critical role of the social and historical context of housing. To this effect, the main
findings in the study are similar to Tippleâs contentions, namely that privatisation leads to
transformations that combat housing stress, that transformations produce economic
multipliers in the locality, that transformations occur outside the basis of secure tenure
and that income is not the most important variable in housing extensions. The study goes
further and suggests the historical context of housing, whereby privatisation is a way of
ensuring a foothold in urban South Africa. Such a foothold in urban South Africa is
important considering the historical exclusion of black people from urban South Africa.
The social context of black housing in South Africa is characterised by a long quest for urban citizenship and housing rights. These characteristics give rise to a distinct housing
environment not observable in the developed countries.
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FLOW CHARACTERISTICS OF GROUNDWATER SYSTEMS: AN INVESTIGATION OF HYDRAULIC PARAMETERSLeketa, Khahliso Clifford 24 May 2013 (has links)
The Institute for Groundwater Studies (IGS) undertook a groundwater surface water interaction project under the funding of Water Research Commission starting July 2010. The Modder River was identified as an appropriate study area since it is located downstream of Krugersdrift Dam and has only been impacted by farming activities.
This thesis aims at investigating the hydraulic parameters and flow characteristics of groundwater in the study area aquifer so as to have a preliminary picture of the groundwater systems of the site prior to the groundwater surface water interaction project takeoff.
The field procedures were performed starting with site inspection, drilling, water level monitoring, pumping tests, tracer tests, and chemical sampling. Geological classification was performed during site inspection and drilling, while soil cover was analysed for texture analysis in the soil science laboratory. Water level monitoring was performed to study the groundwater fluctuations and flow directions with time. Constant rate tests were performed together with recovery tests to determine the transmissivity of the aquifer in the study area while point dilution tracer tests were done to determine the Darcy velocity of the section of maximum flow in the aquifer. In chemical analysis, micro and macro analysis were performed while tritium 3H, Deuterium 2H, and 18-Oxygen were analysed for in isotope analysis. Chemistry and isotope analysis were done to classify water in terms of its source, fate and age.
From all boreholes, at the average depth of 8 meters, an alluvial material was obtained in between the top calcareous soil material and the bottom shale formation. The water level fluctuation trend was similar in all boreholes indicating possibilities of a common aquifer intercepted by all boreholes. Using water level time series, groundwater flow direction was determined to be towards the North-Eastern direction slightly in the direction of local topography while the river flow is westwards. The geometric mean of transmissivity values obtained from a Cooper-Jacob plot is 66 m2/d and the geometric mean for the recharge value from chloride method is 1.7 %. The geometric mean of the Darcy velocity value obtained from different boreholes in the aquifer is 6.9 m/d. These mean values are representative of the whole aquifer.
In addition to flow direction being due to topography, it is hypothesized that the unusual flow direction behaviour is due to the seepage that acts like a natural borehole at the river bank such that a semi-cone of depression is formed towards the North East. In hydrochemistry, the most abundant cation is sodium followed by magnesium and the most abundant anion is T.Alk (carbonates). From a Piper diagram, groundwater was characterized to be calcium magnesium bicarbonate type of water. The SAR of groundwater is low and within the recommended value for irrigation agriculture while the EC is so high that the water is recommended strictly for crops that are not sensitive to brackish water. According to the isotope analysis, the water from the boreholes and seepage seem to have the same isotopic fingerprint. Needless to say that, the water that seeps on the banks is the same water as that from the aquifer that is intercepted by the boreholes. Groundwater plots closer to the global meteoric water line than river water which plots on the evaporation water line, needless to say that, river water is evaporation water rich in 18-oxygen while groundwater experiences less evaporation hence high 16-oxygen content.
The hydrogeology of the area is therefore characterized by the presence of major flow in the gravel material at the average depth of 8 meters.
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FRACTURE CHARACTERISATION OF KAROO AQUIFERSPacome, Ahokpossi Dehouegnon 27 May 2013 (has links)
Fractures are mechanical ruptures in rocks, form by stress (lithostatic, tectonic, and thermal stresses and high fluid pressures) concentrations around flaws, heterogeneities, and physical discontinuities at a variety of scales. In groundwater reservoirs, mainly in those formed within relatively less permeable or hard rocks, connected fractures may form privileged conduits for fluid flow and solute through the rock, and therefore needs to be located and quantitatively (geometry, permeability, and ability to transport solute) appreciated for a better understanding of water flow and mass transport processes in the subsurface. Many techniques have been adapted from petroleum applications to address these issues and are reviewed in the present study with after an overview on geological and geo-mechanical features that evolve fracturing.
Very few existing tools are cost-effective and easy to be performed on the field. The FEC (Fluid Electrical Conductivity) based techniques; mainly the single borehole based ones involve often, relatively cost effective equipments and are simple. The present study focus also on the applicability of âFlowing Fluid Electrical conductivity loggingâ (Tsang et al., 1990; Doughty et al., 2005) and the FEC based dilution test (well dilution) for fracture characterization in the Karoo aquifer. The FFEC is found to be a promising technique for local fracture characterization, mainly in contamination studies (investigation and scenario testing), like in mine environments; and is recommended to be experienced in South-Africa, particularly in the meta-sediments of the Karoo environment. The FEC based dilution test (well dilution) is gaining interest in fracture characterization in South Africa (Mohr Samuel and van Biljon Willem., 2009; Lasher Candice et al., 2009) and has been assessed on two experimental fields in the Karoo Aquifer. The technique is found to constitute a powerful tool for detection of flowing fractures and for qualitative interpretation. The Drost et al (1968) analytical solution suggested for the analysis of the test data (Cook et al., 2001a; Love et al., 2002) have been applied and yielded semi-quantitative values that can be used as first estimation of the groundwater velocity from flowing points into the studied boreholes. However, due to non ideal condition, refinements are still needed mainly for the field procedure and for the consideration of the mass circulation that may be associated with density gradient along the borehole.
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A GROUNDWATER-SURFACE WATER INTERACTION STUDY OF AN ALLUVIAL CHANNEL AQUIFERGomo, Modreck 27 May 2013 (has links)
The study describes the application complimentary geohydrologic tools to investigate the
geohydrological properties of an alluvial channel aquifer and its interaction with the river surface
water resources. Primary field investigations were designed to determine the geologic, hydraulic,
hydrogeochemical and solute transport properties of the alluvial channel aquifer as an important
component of the groundwaterâsurface water (GWâSW) interaction system. The secondary
investigations were then aimed at assessing groundwater discharge and recharge mechanisms of the
alluvial channel aquifer at a local scale (< 1000 m). A water balance model was developed for the
groundwaterâsurface system as a tertiary level of investigation.
Geological characterisation results show the spatial variation in the physical properties of
unconsolidated aquifer materials between boreholes and at different depth. The drawdown
derivative diagnostic analysis shows that the alluvial channel aquifer system response during
pumping can be described by the following major groundwater flow characteristics; Typical Theis
response; transition period from initial Theis response to radial acting flow (RAF); radial acting flow
in the gravelâsand layer and river single impermeable boundary effects. Detailed studies of the
hydrogeochemical processes in the alluvial aquifer system have shown that dissolution of silicate
weathering, dolomite and calcite minerals, and ion exchanges are the dominant hydrogeochemical
processes that controls groundwater quality. Quantitative and qualitative investigations indicate
that the alluvial channel aquifer is being recharged through preferential infiltration recharge as
facilitated by cavities and holes created by the burrowing animals and dense tree rooting system.
Tracer tests under natural gradient were successfully conducted in an alluvial channel aquifer, thus
providing some advice on how to conduct tracer breakthrough tests under natural gradients in a
typical alluvial channel aquifer.
The findings of the study also highlights the value of developing a water balance model as a
preliminary requirement before detailed GWâSW interaction investigations can be conducted. Based
on the theoretical conceptualizations and field evidence it is suggested that studies be conducted to
determine if alluvial channel aquifers can be further classified based on the nature of the hosting
river channel. The classification would split the alluvial channel aquifer into alluvial cover and
fracturedâbedrock, or a combination of the two. The applications of the PhD thesis findings are not
only limited to the case study site, but have important implications for GWâSW interaction studies,
groundwater resource development and protection in areas where groundwater occurs in alluvial
channel deposits.
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WISH AS A WATER MANAGEMENT TOOL IN OPENCAST AND UNDERGROUND COLLIERIESLukas, Eelco 27 May 2013 (has links)
Over the last 15 years the Windows Interpretation System for the Hydrogeologist (WISH) was developed by the author of this thesis. The program is used by numerous mines and consultants all over South Africa and abroad. WISH does not discriminate between mining types as it is just as capable of handling all water issues in the gold mines, platinum mines, iron mines or as the title of this thesis implies coal mines. Many other water related software packages are available. Most of them are developed for a single purpose. (Borehole logs, pumping tests, chemistry graphs or mapping) WISH is different because it can do it all. WISH was developed with the Hydrogeologist in mind. When a graph is requested WISH will create one first and subsequently allow the user to modify the graph. The volume calculations for opencast and underground mines are a breeze and no other existing software can do this with so much ease. Many collieries in South Africa are using WISH, not only for the chemistry and time data capabilities, but also for the management of large volumes of water. Many collieries trust WISH to calculate water capacity and water volumes in the mines. Decisions are taken to build 200 million rand water treatment plants.
This thesis discusses the development and existence of WISH. A comparison with all other (ground) water related software available worldwide followed by a more in detail description of WISH and a quick starter guide on how to create a WISH document. A chapter is dedicated to recharge and decant followed by a discussion on how to use WISH in a real life project.
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COMPARING MODEL CALCULATED GROUNDWATER VOLUMES WITH ALTERNATIVE METHODS IN A MINING ENVIRONMENTBoshoff, Elida 27 May 2013 (has links)
A new opencast coal mining operation is proposed in the Belfast region in
Mpumalanga, South Africa. This proposed operation is the study site that was
investigated in this thesis. The Belfast opencast operation is expected to be
operational for 29 years and coal from mainly the number 2 and 3 seams will be
mined.
The inflow rate of the groundwater was determined by using both analytical and
numerical groundwater methods. The rate at which groundwater flows into the
mine voids are important to estimate before mining commence since this will
determine at what rate groundwater needs to be pumped from the mining pits to
ensure dry and safe working conditions.
In order to obtain site specific data for the study area, several field investigations
have been conducted. These investigations include a geophysical survey, drilling
of monitoring boreholes and pump testing of the monitoring boreholes. These
investigations are done to obtain a better overview of the aquifer conditions in the
study area.
For the study area a numerical groundwater flow model was constructed and the
groundwater inflow was determined by making use of a water budget function.
The analytical approach to determining the inflow included four different methods.
A sensitivity analysis was done on the recharge with the numerical and analytical
methods.
The results from the numerical and analytical approaches were compared to
determine whether the analytical approach is in fact a good way of obtaining
values that relates with the numerically obtained results. If there is a good
correspondence between the analytical and numerical results, the analytical
approach can be regarded as a save and representative way to obtain
groundwater related values. Especially during the early stages of mine planning
analytical methods would be supportive to quickly determine mine related issues
as this will assist in decision making and related cost estimates. From the results obtained in this thesis it can be concluded that the analytical
approaches used during this study, although giving close to numerical answers,
cannot be used in an effective manner in determining groundwater inflows during
the early planning of mining.
The fact that the analytical approaches did not reveal representative values for the
groundwater inflows and also do not correlate with the numerical model results,
does not mean that this will be the case at another site with different
geohydrological characteristics. It is important to note that assumptions are
always made in analytical methods.
It is suggested that further research be conducted in relation with analytical and
numerical modelling of opencast mines. Research should be performed at several
mines to determine whether the relation between the numerical and analytical
approaches display similar trends than was found during this study. These mines
should preferably be on similar geological areas to compare with each other. The
only way to determine whether the analytical methods can in fact be used to get a
representative result is by repetition on several mining sites and also comparing
these values with the numerical model results and also the actual inflow rates from
the mine once mining has started.
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IMPACT AND RISK ASSESSMENT OF CHROMIUM CONTAMINATED GROUNDWATER SITES IN SATURATED AND UNSATURATED ZONESSibanyoni, John 30 May 2013 (has links)
A key challenge for chromium related activities, such as in ferrochromium industries, is the disposal of waste containing chromium slag or dust with hexavalent chromium (Cr(VI)). Various investigations have shown that hexavalent chromium is a serious concern to both environment and human health because of its mobility and carcinogenicity (Fendorf et al.; 2003).
This study evaluates the impact of chromium on groundwater in the unsaturated and saturated zone by human related activities. A South African ferrochromium industry sector based in the Mpumalanga Province, (Middelburg) was selected as a case study to assess a waste dump of ferrochromium slag. The challenges regarding the dumping of slag are the oxidation of trivalent chromium (Cr(III)) to hexavalent chromium, as well as fine dust from the open arc furnaces which contain hexavalent chromium. At the case study site, the historic dump site (HDS), which is not lined, was previously used to dump various waste materials (since 1964), including but not limited to:
ï· Ferrochromium slag
ï· Phenols
ï· Fine dust from open arc furnaces (with hexavalent chromium)
ï· Filter cake (with hexavalent chromium)
Literature studies indicate that trivalent chromium can be oxidised to hexavalent chromium Cr(VI) through presence of moisture, dissolved oxygen and manganese dioxide (MnO4) (EPA, 1994). The literature also indicates that concentration of hexavalent chromium Cr(VI) greater than 1 mg/l imparts a yellow colour (US EPA (1994) which was used as a visual indicator during field assessments at the HDS. The presence of hexavalent chromium was observed at the toe of the dumps and in low lying areas surrounding the dumps with elevated moisture contents. The presence of hexavalent chromium was also confirmed by monitoring results for both surface and groundwater.
The mitigation that has taken place on site, involved the removal of hazardous waste such as fine dust and filter cake with hexavalent chromium from the HDS, and dumping it at a hazardous waste site (Holfontein). Other on-going mitigation at the dump is the usage of ferrous sulphate at the capturing point (infiltration gallery) to reduce hexavalent chromium to trivalent chromium through oxidation-reduction (redox) reaction process. This study has indicated that although some remedial approaches have been performed, the contamination still exists at the site.
The findings of the study assessment have indicated the following:
ï· Boreholes near the process plant indicated contamination by both trivalent chromium and hexavalent chromium.
ï· Dam 4A and 4B have the highest concentration of hexavalent chromium as well as other constituents, such as sulphate (SO4).
ï· Boreholes down-gradient of the HDS indicated pollution by hexavalent chromium, sulphate (SO4) and other parameters.
ï· The western boreholes showed a trend of increasing pollution by sulphate (SO4), though not by trivalent or hexavalent chromium. Background boreholes did not show any pollution.
ï· Contamination to the unsaturated zone is high but also differed when compared to contamination in saturated zones.
ï· Contamination by hexavalent chromium is caused mainly by the fluctuating water table during water spraying (cooling) of hot slag, and due to precipitation in the rainy season.
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