The Power of the Color Spectrum: The Case of Halle Berry and Viola Davis

La industria de Hollywood ha estado dominada principalmente por hombres de raza blanca. Por esa razón, las actrices afroamericanas son el segmento más infravalorado en el cine. El propósito de este trabajo es examinar la relación entre el color de la piel y los rasgos físicos por un lado y los personajes que las actrices afroamericanas han interpretado en el cine comercial. En particular, este trabajo compara los casos de dos actrices contemporáneas, Halle Berry y Viola Davis. Las dos tienen una edad similar y comenzaron su carrera aproximadamente al mismo tiempo, sin embargo tanto la tonalidad de su piel como su físico son marcadamente distintos y los papeles que han interpretado en el cine también han sido distintos. Su caracterización se ha basado en mayor o menor medida en los estereotipos a través de los cuales ha representado a los afroamericanos durante décadas y en un ideal de belleza occidental. Por esta razón, se ha partido de las historias de racismo y sexismo que subyacen en la cultura estadounidense para determinar las formas en que la discriminación por razón de raza y sexo se perpetúa en la actualidad

Mineralogical controls on porosity and water chemistry during O2-SO2-CO2 reaction of CO2 storage reservoir and cap-rock core

Reservoir and cap-rock core samples with variable lithology's representative of siliciclastic reservoirs used for CO storage have been characterized and reacted at reservoir conditions with an impure CO stream and low salinity brine. Cores from a target CO storage site in Queensland, Australia were tested. Mineralogical controls on the resulting changes to porosity and water chemistry have been identified. The tested siliciclastic reservoir core samples can be grouped generally into three responses to impure CO-brine reaction, dependent on mineralogy. The mineralogically clean quartzose reservoir cores had high porosities, with negligible change after reaction, in resolvable porosity or mineralogy, calculated using X-ray micro computed tomography and QEMSCAN. However, strong brine acidification and a high concentration of dissolved sulphate were generated in experiments owing to minimal mineral buffering. Also, the movement of kaolin has the potential to block pore throats and reduce permeability. The reaction of the impure CO-brine with calcite-cemented cap-rock core samples caused the largest porosity changes after reaction through calcite dissolution; to the extent that one sample developed a connection of open pores that extended into the core sub-plug. This has the potential to both favor injectivity but also affect CO migration. The dissolution of calcite caused the buffering of acidity resulting in no significant observable silicate dissolution. Clay-rich cap-rock core samples with minor amounts of carbonate minerals had only small changes after reaction. Created porosity appeared mainly disconnected. Changes were instead associated with decreases in density from Fe-leaching of chlorite or dissolution of minor amounts of carbonates and plagioclase. The interbedded sandstone and shale core also developed increased porosity parallel to bedding through dissolution of carbonates and reactive silicates in the sandy layers. Tight interbedded cap-rocks could be expected to act as baffles to fluids preventing vertical fluid migration. Concentrations of dissolved elements including Ca, Fe, Mn, and Ni increased during reactions of several core samples, with Mn, Mg, Co, and Zn correlated with Ca from cap-rock cores. Precipitation of gypsum, Fe-oxides and clays on seal core samples sequestered dissolved elements including Fe through co-precipitation or adsorption. A conceptual model of impure CO-water-rock interactions for a siliciclastic reservoir is discussed

Geo-environmental approaches for the remediation of acid sulphate soil in low-lying floodplains

Acidity generated from the oxidation of pyrite and other sulphidic compounds that exist at shallow depths in acid sulphate soils (ASS) presents a challenging environmental problem in coastal Australia. The generated acidic groundwater can adversely impact coastal ecosystems, aquaculture and agriculture. Groundwater manipulation using weirs and modified floodgates in creeks and flood mitigation drains in ASS-affected farmland, which has been practiced for over a decade for preventing pyrite oxidation, is not effective in low-lying floodplains due to the high risk of flooding. In this paper, the authors present an overview of their experience in coastal Australia, a critical evaluation of currently practiced geo-environmental remediation methods as well as a demonstration of a pilot permeable reactive barrier (PRB) to control acidic groundwater pollution. The selection of recycled concrete, a commonly available alkaline waste material, and the systematic investigation of its longevity are highlighted through a series of batch and column experiments. In addition, the improvement of the groundwater quality by a pilot PRB using recycled concrete in ASS terrain within the Shoalhaven region of NSW, Australia will be elucidated based on field data collected over the last 3.5 years

Occurrence and consequences of acid sulphate soils and methods of site remediation

The oxidation of sulphides in acid sulphate soils (ASS) causes the acidification of many Australian coastal river systems. The acidity negatively impacts upon coastal ecosystems, aquaculture, agriculture and concrete and steel infrastructure. In the low-lying floodplains, relatively deep surface drains fitted with one-way floodgates lower the watertable, thereby exposing the sulphidic minerals to oxidation. On the Broughton Creek floodplain in SE Australia, four distinct remediation strategies have been developed to tackle the issue of acidification by ASS: (i) simple V-notch weirs that raise the level of the watertable surrounding the drains thereby submerging the pyrite and preventing the further formation of acidity; (ii) modified two-way floodgates that allow the inflow of tidal water into the drains, thereby offering the acidity within the drain before it enters the river and raising the level of the watertable surrounding the drain; (iii) lateral impermeable lime barriers that both prevent oxidation of pyrite by stopping the downward movement of oxygen into the soil and neutralise the acidity in the groundwater; and (iv) permeable reactive barriers (PRB) that passively intercept the groundwater flow and neutralise the acidity. Each remediation strategy has a distinct role to suit the different terrain and groundwater conditions

Selection of permeable reactive barrier materials for treating acidic groundwater in acid sulphate soil terrains based on laboratory column tests

The Shoalhaven region of NSW experiences environmental acidification due to acid sulphate soils (ASS). In order to trial an environmental engineering solution to groundwater remediation involving a permeable reactive barrier (PRB), comprehensive site characterisation and laboratory-based batch and column tests of reactive materials were conducted. The PRB is designed to perform in situ remediation of the acidic groundwater (pH 3) that is generated in ASS. Twenty-five alkaline reactive materials have been tested for suitability for the barrier, with an emphasis on waste materials, including waste concrete, limestone, calcite-bearing zeolitic breccia, blast furnace slag and oyster shells. Following three phases of batch tests, two waste materials (waste concrete and oyster shells) were chosen for column tests that simulate flow conditions through the barrier and using acidic water from the field site (pH 3). Both waste materials successfully treated with the acidic water, for example, after 300 pore volumes, the oyster shells still neutralised the water (pH 7)

Petrography, carbonate mineralogy and geochemistry of thermally altered coal in Permian coal measures, Hunter Valley, Australia

Carbonate minerals commonly occur in coals of many ages and from a utilisation viewpoint can be deleterious. Several studies have been undertaken of the carbonates in the Permian coals of the Hunter Valley, Australia, but few studies use a multi-technique approach. For this study, a combined petrographic, geochemical and mineralogical approach was used to determine the distribution and residence of carbonate minerals in coal that had been intruded by a dyke. The dominant carbonate assemblages comprise primary siderite in inertinite-rich microlithotypes and secondary calcite(–ankerite–dolomite)–dawsonite in vitrinite-rich microlithotypes. The secondary carbonates were found in both the aureole of heated coal and also in an unheated mine-face sample. It is believed that the secondary carbonate minerals precipitated from magma-derived fluids percolating through the coal following the emplacement of the intrusions. The textures and distribution of the secondary carbonate minerals suggest that the temperature and pressure of the fluids may be just as important in developing fractures near dykes (particularly those that have multiple phases of geometries), cleat mineralogy and coal textures as direct heating from the intrusion. The partitioning of primary siderite with inertinite and secondary carbonates with vitrinite indicates that it can be reasonably expected that there would be a partitioning of minerals in various density fractions derived from float–sink tests and consequently a partitioning of elements with inertinite-rich fractions containing elevated Fe levels and vitrinite-rich fractions containing elevated Ca, Mg and Al. This partitioning has implications for the behaviour of the coal during washing and combustion, and the composition of combustion products