Manufacturing a Ceramic Water Filter Press for Use in Nigeria

A significant proportion of Nigerian households lack access to improved and safe drinking water supplies. This has resulted in high incidences of diarrhoeal-related deaths in the country, especially among young children. Several studies have shown that point-of-use water treatment options such as ceramic filtration are effective in reducing the occurrence of water-borne diseases; however, its use in Nigeria has been significantly low. There is a need to build entrepreneurial capacity among local potters and potteries to drive the scale up of ceramic water filter production across the nation in order to create demand for the filters, seeing that huge potential for its sales abounds. However, the high cost of acquisition of the ceramic water filter press, which is the most essential equipment in the production of the water filters, is a major limitation to the scale up of ceramic water filter production in the country. The goal of the study was to manufacture a ceramic water filter press, by adapting an existing design, using locally sourced materials and manpower, to achieve lower cost. The resulting filter press cost approximately $1000, proving the viability and cost efficiency of the local manufacture of ceramic water filter presses in Nigeria

CO2-brine injectivity tests in high co2 content carbonate field, sarawak basin, offshore east Malaysia

We conducted relatively long duration core-flooding tests on three representative core samples under reservoir conditions to quantify the potential impact of flow rates on fines production/permeability change. Supercritical CO2 was injected cyclically with incremental increases in flow rate (2─14 ml/min) with live brine until a total of 7 cycles were completed. To avoid unwanted fluid-rock reaction when live brine was injected into the sample, and to mimic the in-situ geochemical conditions of the reservoir, a packed column was installed on the inflow accumulator line to pre-equilibrate the fluid before entering the core sample. The change in the gas porosity and permeability of the tested plug samples due to different mechanisms (dissolution and/or precipitation) that may occur during scCO2/live brine injection was investigated. Nuclear magnetic resonance (NMR) T2 determination, X-ray CT scans and chemical analyses of the produced brine were also conducted. Results of pre- and post-test analyses (poroperm, NMR, X-ray CT) showed no clear evidence of formation damage even after long testing cycles and only minor or no dissolution (after large injected pore volumes (PVs) ~ 200). The critical flow rates (if there is one) were higher than the maximum rates applied. Chemical analyses of the core effluent showed that the rock samples for which a pre-column was installed do not experience carbonate dissolution

The Study of Supercritical Carbon Dioxide Trapping Behaviour in Carbonate Reservoirs Through Pore-Scale Imaging Analysis

Severe climate change has urged the energy industry to revolutionalise the conventional technologies at pace to curb greenhouse gasses emission for more sustainable future. Carbon Dioxide (CO2) storage at subsurface geological formation remains as the most effective technique to store massive quantity of CO2 safely and permanently. Nonetheless, the flow and trapping behaviours of CO2 at supercritical condition within geological formation are very complex, particularly for the carbonate rocks attributed to the wide spectrum of rock fabrics, pore geometries and structures. This study aims to investigate the pore interconnectivity and residual CO2 trapping during the drainage and imbibition processes within porous media through digital rock technology. Native cores from three carbonate fields with different rock characteristics were plugged to obtain representative samples for the pore-scale coreflooding experiments. Brine and supercritical CO2 were injected into core plugs at temperature up to 120 °C and pressure up to 3000 psi. X-ray images of the saturated core plugs were obtained through micro computed tomography (Micro-CT) facilities after injection of 10 pore volume (PV) of CO2 and 5 PV of brine. Porosity, pore interconnectivity, fluid occupancy, saturation profiles and CO2 ganglia size distribution were measured and studied through the pore-scale imaging analysis. The results indicate that the saturation of CO2 after drainage and imbibition are strongly dependent on the local rock heterogeneity, specifically the presence and distribution of micropores within the rocks. All samples evidently show that micropores play critical role in pore interconnectivity. CO2 ganglia in one sample was observed to be well connected initially but fragmented into smaller sizes after brine imbibition and, lastly, there was no CO2 percolation within the pore network if the flow rate was too low. This paper presents a detailed study in investigating the flow and trapping behaviour of CO2 at supercritical state, providing new insights to the important factors which influence the CO2 trapping. Deeper understanding of the flow and trapping mechanisms is essential to formulate an effective CO2 storage development plan, ensuring minimum injectivity and containment risk throughout the storage period.</p

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We conducted relatively long duration core-flooding tests on three representative core samples under reservoir conditions to quantify the potential impact of flow rates on fines production/permeability change. Supercritical CO2 was injected cyclically with incremental increases in flow rate (2─14 ml/min) with live brine until a total of 7 cycles were completed. To avoid unwanted fluid-rock reaction when live brine was injected into the sample, and to mimic the in-situ geochemical conditions of the reservoir, a packed column was installed on the inflow accumulator line to pre-equilibrate the fluid before entering the core sample. The change in the gas porosity and permeability of the tested plug samples due to different mechanisms (dissolution and/or precipitation) that may occur during scCO2/live brine injection was investigated. Nuclear magnetic resonance (NMR) T2 determination, X-ray CT scans and chemical analyses of the produced brine were also conducted. Results of pre- and post-test analyses (poroperm, NMR, X-ray CT) showed no clear evidence of formation damage even after long testing cycles and only minor or no dissolution (after large injected pore volumes (PVs) ~ 200). The critical flow rates (if there is one) were higher than the maximum rates applied. Chemical analyses of the core effluent showed that the rock samples for which a pre-column was installed do not experience carbonate dissolution

Evaluative Profiling of Arsenic Sensing and Regulatory Systems in the Human Microbiome Project Genomes

The influence of environmental chemicals including arsenic, a type 1 carcinogen, on the composition and function of the human-associated microbiota is of significance in human health and disease. We have developed a suite of bioinformatics and visual analytics methods to evaluate the availability (presence or absence) and abundance of functional annotations in a microbial genome for seven Pfam protein families: As(III)-responsive transcriptional repressor (ArsR), anion-transporting ATPase (ArsA), arsenical pump membrane protein (ArsB), arsenate reductase (ArsC), arsenical resistance operon transacting repressor (ArsD), water/glycerol transport protein (aquaporins), and universal stress protein (USP). These genes encode function for sensing and/or regulating arsenic content in the bacterial cell. The evaluative profiling strategy was applied to 3,274 genomes from which 62 genomes from 18 genera were identified to contain genes for the seven protein families. Our list included 12 genomes in the Human Microbiome Project (HMP) from the following genera: Citrobacter, Escherichia, Lactobacillus, Providencia, Rhodococcus , and Staphylococcus. Gene neighborhood analysis of the arsenic resistance operon in the genome of Bacteroides thetaiotaomicron VPI-5482, a human gut symbiont, revealed the adjacent arrangement of genes for arsenite binding/transfer (ArsD) and cytochrome c biosynthesis (DsbD_2). Visual analytics facilitated evaluation of protein annotations in 367 genomes in the phylum Bacteroidetes identified multiple genomes in which genes for ArsD and DsbD_2 were adjacently arranged. Cytochrome c , produced by a posttranslational process, consists of heme-containing proteins important for cellular energy production and signaling. Further research is desired to elucidate arsenic resistance and arsenic-mediated cellular energy production in the Bacteroidetes

Public knowledge and beliefs about depression among urban and rural Malays in Malaysia

BACKGROUND: This study examined knowledge and beliefs about depression among Malaysian Malays varying in socioeconomic status. METHODS: A total of 153 urban and 189 rural participants completed a questionnaire in which they had to identify two cases of depression and rate a series of items about the causes and best treatments for depression. RESULTS: Results showed that urban participants were more likely to use psychiatric labels ('depression') for the two vignettes, whereas rural participants tended to use more generic terms ('emotional stress'). CONCLUSION: Principal components analysis (PCA) showed that beliefs about the causes of depression factored into five components, of which stressful life events was most strongly endorsed by both groups. PCA of treatment items revealed four stable components, of which religious factors were most strongly endorsed. There were also a number of significant between-group differences in the endorsement of these factors (eta(p) (2) = .03-.11), with rural participants generally rating supernatural and religious factors more strongly than urban Malays. These results are discussed in relation to mental health literacy programmes in Malaysia